Please Help!! My Computer keeps shutting down by itself?

I ran this Hi Jack and here are the results. Are any of these viruses. i am running Windows XP%26gt;%26gt;

Logfile of HijackThis v1.99.1

Scan saved at 3:01:20 PM, on 9/2/2007

Platform: Windows XP SP2 (WinNT 5.01.2600)

MSIE: Internet Explorer v6.00 SP2 (6.00.2900.2180)

Running processes:

C:\WINDOWS\System32\smss.exe

C:\WINDOWS\system32\winlogon.exe

C:\WINDOWS\system32\services.exe

C:\WINDOWS\system32\lsass.exe

C:\WINDOWS\system32\svchost.exe

C:\WINDOWS\System32\svchost.exe

C:\WINDOWS\system32\svchost.exe

C:\WINDOWS\system32\spoolsv.exe

C:\PROGRA~1\Grisoft\AVG7\avgamsvr.exe

C:\PROGRA~1\Grisoft\AVG7\avgupsvc.exe

C:\PROGRA~1\Grisoft\AVG7\avgemc.exe

C:\WINDOWS\system32\cisvc.exe

C:\Program Files\McAfee\McAfee AntiSpyware\Msssrv.exe

C:\WINDOWS\system32\nvsvc32.exe

C:\Program Files\Common Files\New Boundary\PrismXL\PRISMXL.SYS

C:\WINDOWS\system32\svchost.exe

C:\WINDOWS\system32\cidaemon.exe

C:\WINDOWS\Explorer.EXE

C:\Program Files\NVIDIA Corporation\NvMixer\NVMixerTray.exe

C:\Program Files\Java\jre1.

Please Help!! My Computer keeps shutting down by itself?hijackthis

It may not be a virus that is causing the problem... when was the last time you cleaned the computer? When you computer gets really dusty inside it can cause the fans to stop working and this causes your comp to overheat. When your comp overheats it turns itself off to protect itself from serious damage. Here is a guide to clean out your comp...