Critical system errors

slt j ai un probleme une message critical system errors apparait. fai 1 scan de mon pc avec hijackthis et voici le resultat:

Logfile of HijackThis v1.99.1
Scan saved at 18:17:29, on 07/11/2006
Platform: Windows XP SP1 (WinNT 5.01.2600)
MSIE: Internet Explorer v6.00 SP1 (6.00.2800.1106)

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\spoolsv.exe
C:\WINDOWS\Explorer.EXE
C:\Program Files\MSN Messenger\msnmsgr.exe
C:\Program Files\Alwil Software\Avast4\aswUpdSv.exe
C:\WINDOWS\System32\Ati2evxx.exe
C:\WINDOWS\System32\GEARSec.exe
C:\WINDOWS\System32\irdvxc.exe
C:\Program Files\Analog Devices\SoundMAX\SMAgent.exe
C:\Program Files\Intel\Intel(R) Active Monitor\imonnt.exe
C:\Program Files\Mozilla Firefox\firefox.exe
C:\WINDOWS\System32\svchost.exe
C:\Program Files\Shareaza\Shareaza.exe
C:\Documents and Settings\Batou\Bureau\programe\Scanner.exe.exe

O4 - HKCU\..\Run: [msnmsgr] "C:\Program Files\MSN Messenger\msnmsgr.exe" /background
O17 - HKLM\System\CCS\Services\Tcpip\..\{2542378C-8854-47BF-A8AC-1D69C4529B0E}: NameServer = 86.64.145.142 84.103.237.142
O17 - HKLM\System\CS1\Services\Tcpip\..\{2542378C-8854-47BF-A8AC-1D69C4529B0E}: NameServer = 86.64.145.142 84.103.237.142
O23 - Service: avast! iAVS4 Control Service (aswUpdSv) - Unknown owner - C:\Program Files\Alwil Software\Avast4\aswUpdSv.exe
O23 - Service: Ati HotKey Poller - Unknown owner - C:\WINDOWS\System32\Ati2evxx.exe
O23 - Service: GEARSecurity - GEAR Software - C:\WINDOWS\System32\GEARSec.exe
O23 - Service: Intel(R) Active Monitor (imonNT) - Intel Corp. - C:\Program Files\Intel\Intel(R) Active Monitor\imonnt.exe
O23 - Service: Network helper Service (MSDisk) - Unknown owner - C:\WINDOWS\System32\irdvxc.exe" /service (file missing)
O23 - Service: Intel NCS NetService (NetSvc) - Intel(R) Corporation - C:\Program Files\Intel\NCS\Sync\NetSvc.exe
O23 - Service: SoundMAX Agent Service (SoundMAX Agent Service (default)) - Analog Devices, Inc. - C:\Program Files\Analog Devices\SoundMAX\SMAgent.exe

pouvez vous m aider ?? svp