Winbook J4 problem

My Winbook J4 laptop shuts down unexpectedly, after several (too fast to count) short beeps. It usually happens when I try to download updates to spy ware programs (Pest Patrol, Spybot Search and Destroy) also when I try a full virus scan, using Avast!. The scan works with Stinger, Pest Patrol or AdAware and comes out clean. Spybot scan will shut down the computer.
I have been in touch with Winbook's tech. support and they don't have a clue as to what the problem might be. The computer is a 2.4 MHz. Pentium 4, Windows XP no Service Pack 2, about 16 months old.
I do not believe that a virus is the problem; the computer never ran without virus protection or a firewall. Any suggestions would be appreciated.

Problem resolved! Thanks to Google, I found out that the accumulated dust on the inside of the laptop causing the problem. After vacuuming and mainly blowing out the amazing amount of dirt, the computer is like new again. Hope this will prevent someone to go through this annoyance.

When you cleaned out the dust and dirt from the computer, did you have to partly disassemble it? Or did the dust come mostly from the keyboard? Please explain, because I have much the same problem with my laptop. James :cool:

James, I did not disassemble the laptop, only vacuumed and blew compressed air through all openings, especially where the fans are. You might blow the air first, and then vacuum. The keyboard seemed clean; most dirt was in the fan area. The computer is still perfect, I could not cause a shutdown, before it shut down every time I did a virus scan.
You will be surprised the amount of dirt accumulates and will come out!

Thank you very much! I appreciate your posting back to give me a headsup! James :cool: