Before calling for service, you should take a look at your computer. A little common sense could help solve simple problems of hardware and software.
Restart the computer. Many software problems will be corrected when you do this.
Check the cables. Is the keyboard not working? Make sure it is plugged in. Is the mouse not responding? Check your plug.
Check the power source. Plug a lamp into the same outlet that is connected to your computer and you will know if the equipment is being supplied with energy.
Make sure the computer and monitor are plugged in.
Disconnect any peripheral devices. This can include the printer or scanner. Then restart the computer.
Listen for unusual sounds. Is it working the cooler (fan)? Is the hard drive making noises?
Open the cabinet. See that no cables are disconnected or poorly connected.
Boot your computer from an external boot disk. This can be the CD that comes with the operating system of your computer.
If you finally decide to call for service, write an accurate description of the problem and what you were doing when it happened. Write down any error messages you see. Try to replicate the problem in the presence of the technician.
Be as specific as possible when talking to the technician. For example: "Every time I start my computer, an icon with a question mark appears. Rescue CD with the computer starts normally."
Computers tend to collapse or "hang" when their hard disks are very loaded. To free up space delete all unnecessary files and then remember to empty the Recycle Bin.
When working on your computer, remember to turn it off but unplug the power cable stabilizer. Touch the surface of the source to earth (to mass) before handling any circuit of the team, thus ensuring that any discharge will affect the components of the machine.