1.  Go to Start >  Control Panel, and then double click Security Center.

2. In the Windows Security Center window click Windows Firewall.

3. Windows Firewall window will appear, click Off (not recommended) radio button to shut down Windows Firewall and then click OK .

You can also disable the Windows Firewall with right click on network icon in the lower right corner and then select Change Windows Firewall settings.

Typically, a power supply is selected depending on the required power of individual power lines. As you probably know, the main load falls on the 12V line, so exactly the power provided by this line is very important. Many users make mistake taking the maximum values of current provided by any individual power line and multiply them by the voltage to obtain the output power. That is wrong because the 3.3V and 5V as well as different 12V lines are dependent on one another and that’s why in the specifications for +3.3 V, 5V and +12 V is given their combined power.

To determine what power you need you have to calculate the consumption of your computer components. There are many online calculators, which you can use for this purpose, but you should know that there is no such situation in which all components are loaded to their maximum values. For example if you have two hard drives and one optical drive in the worst case you will have two active working devices. Also in 3D games and applications the mainly loaded device will be the video card, unlike the CPU which will be away from its maximum load. It is also possible the opposite situation, where the processor performs havy calculations, while the video card stays almost unused. Typically, the actual values are about 75-80% of those made by such calculators, but if you add additional capacity for future upgrades, the values calculated in such a way would be quite normal. For a modern computer, as a minimum can be considered values of approximately 350W.

The next thing that you should pay attention to, when purchasing a new power supply is the energy efficiency. The higher values mean that your power supply will convert the voltage from the electrical network more effectively and of course it will produce less heat and noise. Most widely used power supplies have an energy efficiency ratio of about 70-75% but higher-quality power supplies can be over 80% efficient.

Most power supplies are equipped with 80mm or 120mm cooling fans. Larger fans recommended because of the small amount of noise they produce compared with the 80mm fans. There are also the so-called “completely silent” models without fans. They have specially designed cooling system with high efficiency, but are usually considerably more expensive and their power is limited to about 300W – 500W.

Another important requirement for the power supply is to have a sufficient number of connectors, which can save you a lot of problems when adding new hardware. There are also Modular Power Supply Units in which the users can modify the power connectors to suit their personal needs. Unlike the conventional design where power cables are permanently connected to the power supply, a modular power supply provides an option allowing unused cables to be detached from it. By allowing cables to be detached, modular cabling can help you not only to reduce the clutter of unused cables but also improve the airflow within the case.

Typically, manufacturers provide between 6 months and 1 year warranty for batteries, that includes their normal operation, but doesn’t refer to the reduction of the working time of a battery due to its wear and reduced capacity because these factors are highly dependent on how the battery is used. In addition – in the cheapest laptops you will not find the best quality batteries, because the manufacturers’ choice of batteries depends mostly on the  cost of final product. You should also know that the quality assessment of the batteries is impossible without special laboratory equipment, so it is advisable to choose batteries with a longer warranty.
If you travel frequently and you have to use your laptop mainly for work on battery, my advice is to always have a spare battery, with a higher capacity (if possible). It should be noted that finding batteries for brands like HP, Toshiba, Lenovo and Dell is relatively easy because these manufacturers have established themselves as leaders in the production of mobile computers and already have authorized service centers and stores worldwide. In fact, except at the official distributors, batteries for almost all brands of laptops can be found at ebay. The good news is that there you can find non-original batteries (these are not produced by the manufacturer of your laptop) as very often their price is times lower than the original price of batteries offered by distributors. Of course, this doesn’t apply to the specialized batteries that are found in most expensive laptops but I think it makes no sense to pay over $ 100 for a “regular” battery, as there will be hardly a difference in the quality of the original and non-original batteries in most cheaper notebooks.

Capacity of the Li-Ion Battery.

In most cases, the battery capacity indicated by the manufacturer is very different from what Windows, or any standard software can see and use. According to Windows, 0% of capacity, actually means that the battery has a minimum balance of energy which is necessary to be maintained, because otherwise it will stop functioning. My advice is to not store batteries with such a minimum charge for a longer period of time, because there is a real danger that the battery could be discharged completely, and this can be fatal for it. The maximum capacity is theoretical and it will change over the time – it’s an inevitable part of aging of the battery, but its effects can be minimized. Moreover, the maximum capacity generally ranges – i.e. battery with capacity of 4200 mAh could easily be over 4500, but may be 4000 mAh. Of course this can not be measured in advance and is a result of the production technology of these batteries.

Working conditions.

Lithium-ion batteries do not like high temperatures. If the battery operates at 0 degrees celsius, the discharge time will be longer than if it operates at higher temperatures, but at 0 degrees will be difficult to charge the battery. Temperatures over 80 degrees are  potentially dangerous not only for the battery, but also for the device powered by it. Operating temperature is important because these batteries produce heat when discharging (i.e. when used), which increases their internal resistance and reduces the output voltage. This process accelerates the discharging of the battery, leading to a reduction of its working time. In laptop, batteries are usually located at the bottom of the device near heat sources, which makes their cooling a little more difficult.

Li-Ion batteries are strongly influenced by the ’strength’ of consumption ( i.e. the rapid discharging caused by high load shortens the time to work). Therefore, manufacturers use batteries with more cells, because the speed of increase of their internal resistance is less than the speed at which this happens to batteries with a smaller number of cells.

It is more practical to use your laptop in power saving mode not only because it will work longer due to decreased energy consumption, but also because of reduced power requirements – more intensive use of the CPU greatly reduces the time on battery. This means that it is not a good idea to play games while running on battery because the laptop thus consumes more power and the stored energy is going faster.

Storage method of Li-Ion Batteries.

Lithium-ion batteries have very low self-discharge rate – this means that under ideal conditions, battery charge decreases very slowly until exhausted. This self-discharge depends on the ambient temperature and is lowest at lower temperatures. It also depends on the level of charge which means that if the battery is fully charged, its self-discharge rate will be higher. The experts recommend a level of charge for storage of approximately 40% and storage at temperatures below 10 degrees.

Recharging Li-Ion batteries.

Unlike other types of batteries, where every charge ( regardless of how much charge is in the battery ) is called a”cycle”, because of the way of charging in lithium-ion batteries, a “cycle” means the sum of charges, during which the battery charge has reached its total capacity. This means that whatever the level of charge, one “cycle” will be made only after the battery was discharged and after that recharged to a total of 100% of its capacity. In other words, every recharge by itself does not represent a complete cycle. The sum of these charges, which form a 100% charge, may be identified as a “cycle”. Recharging is also important for the battery life duration, because it should be performed in several stages, which are sometimes skipped by manufacturers in order to accelerate the process, by using higher voltage during the charge. This does not concern you, as ordinary user, because typically you can not control it – the laptop manages the voltages for charging by itself.
Unlike old NiCd or NiMH batteries, Li-Ion batteries do not suffer from the “memory” effect, that limits their maximum capacity. As you probably know to eliminate this effect manufacturers recommend an occasional, complete discharge of NiMH batteries followed by a full recharge. Fortunately this doesn’t apply to the lithium-ion batteries. This advantage, along with the reduced weight and better capacity, is one of their main advantages, which makes them relatively easy to use, especially in devices like laptops and phones, where you have no control over the recharging process. Anyway, I think it is almost impossible to completely discharge your battery, because Windows will usually indicate that the charge is running low when its value reaches 10% and computer will be shut down upon reaching the 5% charge in order to avoid any loss of information. However, you will not lose anything if you perform the above recharging process every 2 months.

Remove cooling fan.

1. Remove four screws marked on the picture below.

2. Remove three screws securing the fan and disconnect fan cable from motherboard.

3. Remove the fan.

As you can see the heatsink is clogged with dust, which stops the air flow passing through it. For cleaning  I  suggest using compressed air.

Applying new thermal grease on CPU.

1.To apply new grease you have to remove four screws securing heatsink to the chassis.

2. Now carefully lift up the heatsink.

As you probably know thermal grease (or thermal compound ) helps for the better conducting of heat between the CPU and heatsink. In this laptop the heatsink covers both the CPU and video chips.  The video uses thermal pad to conduct heat to the heatsink and that’s why you will find thermal grease only on the CPU. If it looks dry, you’ll have to replace it with new grease, but in this case you first have to clean the rests of thermal compound that remain on the CPU and heatsink. I would suggest using soft cloth dampened with alcohol or acetone.

Now when both surfaces – of processor and cooler are clean you can apply a thin layer of new thermal grease on the CPU chip (black part).

It has to be thick enough ( but not too thin ) to ensure that the heatsink and CPU are in good contact. Next, carefully install the heatsink over the processor and tighten four screws.

CAUTION: Before you begin any of the following procedures, turn off the laptop , unplug the power adapter and remove the battery. Note that computer parts are very sensitive to static electricity so ground yourself before touching anything inside you computer by using grounding strap or touch a metal faucet  pipe.

1.Remove all marked screws securing RAM, CPU and WLAN cover.

2.Remove four screws securing the keyboard.

3.There are four latches on the top of the keyboard. Using small flat screwdriver press each of the latches down until the keyboard is released.

4.Carefully insert small screwdriver between the top side of the keyboard and notebook case and lift up the keyboard. Be careful with the ribbon cable because it is very short and any possible damage would mean buying a new keyboard.

5.Place the keyboard upside down so you can access the cable connector underneath.

6. As you can see the keyboard cable is plugged into the connector on the motherboard so you’ll have to unlock the connector before removing the cable.  On the picture below the cable connector is shown in locked position.

On the following picture, the same connector is shown in unlocked position.

7. Now you can pull the keyboard cable from the connector and remove the keyboard.

8. When installing the new keyboard align the five securing tabs on the front of the keyboard with the slots on the upper case.

9. Ensure that all five keyboard securing tabs are engaged in their respective slots and press the down on each of the four latches until you hear a clicking which means that they are locked.

Instructions.

For this guide I will use DVD writer LG GSA-H55N, but I think the disassembly process would be similar to many other models.

1. Important: The first and the most important thing to do before you start is to take care of your own safety,  so be sure to turn off the computer and unplug the power cord from the outlet.

2. Open the computer’s case according to the user’s manual provided by manufacturer.

3. Remove data and power cables going into the back of the optical drive.

4. Now remove four screws securing drive to the sides of the drive bay, and slide it out of the computer.

Now comes the tricky part. You’ve probably seen that the optical drive case consists of two metal parts, but in order to separate them, you must remove the front panel of the device. This can be easily done by opening the disc tray. For this purpose I’m using an external power adapter, but you can use one of the power cables of your computer’s power supply unit. In such a case you must be very careful!

5. To open disc tray simply connect the power cable and press the Eject button.

6. Unlock two clips, fixing the front panel.

7. Remove four screws marked on the picture.

8. Remove the lid and gently lift up the mechanics.

Now you can clean the lens of your optical drive with a cotton swab, slightly moistened with alcohol.

1. Battery Care.

Today all modern notebooks and netbooks are equipped with lithium-ion batteries. Along with their advantages over the other types of batteries, they have several characteristics that must be considered in order to preserve their nominal capacity for a longer period of time.

Lithium-ion batteries are sensitive to ambient temperature. They may not be used at temperatures below zero degrees, since this significantly reduces their capacity.

Although lithium-ion batteries do not suffer from the “memory effect”, they still must be regularly “trained”. It means that you should completely dissolve and then recharge your battery at least every 2-3 weeks. In some notebooks for that purpose there is special function, accessible in the BIOS,but this can be done manually, by stopping all energy saving features and allow the laptop to completely shut down by itself.

If you are planning during most of the time to use your notebook connected to the AC adapter (e.g. use it as a desktop replacement) it is recommended to remove the battery (for example – when it’s half charged) and put it in place with low temperature and away from direct sunlight. Of course, you should consider that in case of power supply interruption you will lose your data.

Contacts of the battery could be oxidized, and even the thinnest oxide layer may reduce the transfer of power from your battery to the notebook. Therefore it is recommended to clean the battery’s metal contacts every 2-3 months. Unfortunately I can’t give you an accurate advice about how it’s best to make such cleaning, but however, do not use sandpaper. Maybe it is best to do that with rubbing alcohol on a damp cloth.

2. How to minimize the energy consumption.

The time for autonomous work of the laptop depends not only on the capacity of its battery, but also on its consumption depending on several factors such as characteristics of the computer hardware and software, and the system settings.

You must pay more attention to the hardware when purchasing you computer. If the requirement for maximum operating time of battery is critically important, maybe you should look for device equipped with more energy efficient processor and a solid-state storage drive, which requires less power, since there are no spinning parts. Moreover, the large amount of memory also saves some operations of the operating system, which reduces the unnecessary energy consumption. Additional time to work can be gained by choosing the optimal operating system. Of course the choice of operating system also depends on the hardware capabilities of your computer. According to unofficial data, portable computers with Windows 7 running about 20-30 minutes longer with a single battery charge, compared to computers running Windows XP or Windows Vista. Anyway, it is recommended that the operating system is updated regularly. Another important thing is the regular defragmenting of hard drive that must be made at least every 2-3 months. Defragmenting allows your operating system to rearrange the file fragments so they are closer together on the hard drive, decreasing the time your system must spend searching for files. That’s why an optimization of your hard drive can provide you with additional battery power.

3. Extension of the battery operating time.

Above methods are important for maintaining the good condition of your battery, but there are ways allowing you to keep its capacity while operating with the computer. You can use those tips below to reduce the consumption of your laptop to a minimum. This will help you not only to achieve long operating time on battery, but will also reduce cases of rapid depletion of capacity, which could harm the battery.

When switching to battery power you have to ensure that the appropriate scheme for power management is chosen. Use the power management settings built in your operating system.

It is important to keep the temperature regime, so avoid extreme temperatures.  Laptop must be placed on a hard flat surface for better access of air to the cooling fan. Your laptop will operate more efficiently when it’s cooler so make sure to clean out your air vents regularly.

Turn off all peripheral devices that are not currently in use (e.g, Wi-Fi adapter or Bluetooth) and unplug external devices such as a USB mouse or an external drive.

Configure your display to turn off when not in use. It is also recommended to set the minimum adequate levels of display brightness and volume.

Use energy-saving features such as Hibernate or Standby. Hibernating a PC will actually save more power than when in standby mode because its state will be saved as it is, but the computer will shut down completely.

Avoid multitasking and close all the applications that run in the background on your computer. Shut down everything that isn’t crucial and use only what you realy need at any given time.

You should also avoid using the optical drive if possible. Optical drives consume larger amounts of energy compared with hard drives, so if you need data stored on a CD or DVD it’s recommended to copy it to your laptop’s hard drive before traveling.

Since usually a full stop of the propeller is not a sudden, there are some signs indicating that something is wrong. One of them is the increased noise emitted by computer sometimes. Usually that same sound is heard when you first start the system and then it stops by itself. After some time, however, that sound becomes a constant grinding noise, which indicates that the fan is permanently damaged, and its rotation is seriously hampered. Therefore, if any of these signs is present in your computer, do not hesitate to clean the power supply unit, because this may prolong its life and help you save money.

Important: With opening the computer’s case  you may lose your warranty, so be sure to check the documentation that comes from the company where it was purchased. If the warranty period has already expired, you can continue safely with the cleaning operation. Otherwise it may be better to take it to the workshop of the company where a specialist can take care of its cleaning. However, if you decide to perform the next operation, the only equipmemt you will need is a screwdriver, cleaning cloth, brush and can of compressed air.

OK. Let’s start.

The first and perhaps the most important thing to do before you start is to take care of your own safety,  so be sure to turn off the computer and unplug the power cord from the outlet.

1. Open the case and unplug all possible connectors that connect the power supply with the motherboard, CD / DVD-ROM devices, hard disks and floppy (if any exist).

2. Then remove four screws fixing the power supply unit to the rear panel of the computer. Keep in mind that the power unit is heavy and when you remove the last screw it could fall inside the computer and broke some of the components (for example, mothrboard or processor). Therefore it is better to hold the power unit with one hand while removing screws.

3. Once you remove the power block, it is time to proceed with its opening. For this purpose you have to remove several small screws (four in this case).

4. Once you get access to the electronic components of the power block, you must clean the accumulated dust, since it prevents them from better cooling. For this purpose you can use a synthetic bristle brush and compressed air spray.

Removal of the fan is pretty easy. All you need to do is to remove four screws, securing the fan to the metal case .

Now is the time to mention that according to its degree of wear, sometimes it’s better to replace it with new one, instead of cleaning it (especially if it makes loud or strange “buzzing” noises, which indicates permanent damage. If the wires are soldered to the curcuit board, your task becomes little more complicated, so it may take more time. The important here is the proper connection of wires when soldering them back to the circuit board.

After completion of the cleaning you can reassemble the power unit and install it back in the computer, but do not forget to connect all of its connectors to the corresponding  devices.

CAUTION: Before you begin any of the following procedures, turn off the laptop , unplug the power adapter and remove the battery. Note that computer parts are very sensitive to static electricity so ground yourself before touching anything inside you computer by using grounding strap or touch a metal faucet  pipe.

1.  The cooling fan can be accessed from the bottom of the laptop. All you have to do is to turn over the laptop and remove all marked screws from the bottom of the laptop.

2. Disconnect connector of the fan cable from the motherboard.

3. Remove two screws securing the cooling fan.

4. Now you can clean the cooling module and remove accumulated dust from the heat sink and fan using compressed air or brush.

If the cooling fan has  become very noisy or started  to make strange grinding sounds, then maybe it’s time to be replaced it with a new one.

You can find the model and version of the motherboard with programs like CPU-Z, Everest or PC Wizard. For example: to see information about the motherboard in CPU-Z just start the program and click the Motherboard tab.

If you can’t find any application that can do the job or you don’t have access to the Internet to download it, the next thing that you can do is to open the computer’s case and to look for the model near the PCI slots, AGP slot, PCI-express slot or between the processor and the RAM slot, as it is shown in the picture below.

Be sure to check the documentation that comes with your computer or you may lose your warranty. In case if you can’t open your computer you can see the model name at the computer startup. Use the key “Pause Break” on your keyboard (when you see the first BIOS POST screen) to stop loading the system and see what is the model. With newer motherboards that can be quite difficult because they pass through the Welcome screen very quickly, even before the monitor is started, so to try to press the key (immediately after the start) without waiting for displaying a picture and wait. If you fail the first time try again.