Mon ordi plante souvent.. Virus????

Bonjour à tous,
Je doute que mon pc ai des virus.
J'ai effectué un rapport avec hijackthis de mon pc, mais j'y comprends rien, est ce que quelqu'un pourrais m'aider svp? merci beaucoup...
Mon rapport :

Logfile of HijackThis v1.99.1
Scan saved at 13:40:58, on 22/04/2007
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\ZoneLabs\vsmon.exe
C:\Program Files\Alwil Software\Avast4\aswUpdSv.exe
C:\WINDOWS\system32\ZoneLabs\avsys\ScanningProcess.exe
C:\WINDOWS\system32\ZoneLabs\avsys\ScanningProcess.exe
C:\WINDOWS\Explorer.EXE
C:\Program Files\Alwil Software\Avast4\ashServ.exe
C:\WINDOWS\system32\LEXBCES.EXE
C:\WINDOWS\system32\spoolsv.exe
C:\WINDOWS\system32\LEXPPS.EXE
C:\PROGRA~1\3BSOFT~1\WINDOW~2\WINDOWS CLEAN-UP PRO.Exe
C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
C:\Program Files\NVIDIA Corporation\NvMixer\NVMixerTray.exe
C:\WINDOWS\system32\LXSUPMON.EXE
C:\PROGRA~1\Grisoft\AVG7\avgcc.exe
C:\Program Files\Zone Labs\ZoneAlarm\zlclient.exe
C:\Program Files\MSN Messenger\msnmsgr.exe
C:\WINDOWS\system32\ctfmon.exe
C:\Program Files\Windows Registry Repair Pro\RegistryRepairPro.exe
C:\PROGRA~1\Grisoft\AVG7\avgamsvr.exe
C:\PROGRA~1\Grisoft\AVG7\avgupsvc.exe
C:\PROGRA~1\Grisoft\AVG7\avgemc.exe
C:\Program Files\Fichiers communs\Microsoft Shared\VS7Debug\mdm.exe
C:\WINDOWS\system32\nvsvc32.exe
C:\Program Files\Alcohol Soft\Alcohol 120\StarWind\StarWindService.exe
C:\WINDOWS\system32\svchost.exe
C:\Program Files\Alwil Software\Avast4\ashMaiSv.exe
C:\Program Files\Alwil Software\Avast4\ashWebSv.exe
C:\PROGRA~1\ZONELA~1\ZONEAL~1\MAILFR~1\mantispm.exe
C:\WINDOWS\system32\WgaTray.exe
C:\Program Files\Internet Explorer\IEXPLORE.EXE
D:\Logiciel\hijackthis\Scanner.exe

R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://neufportail.fr/
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Liens
O2 - BHO: Adobe PDF Reader Link Helper - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Adobe\Acrobat 7.0\ActiveX\AcroIEHelper.dll
O2 - BHO: AKHelper.HelperBHO - {911C4A8E-0F75-4B83-BEB9-02BDDF29D11E} - C:\Program Files\3B Software\3B Ad Blocker Pro\AKHelper.dll
O3 - Toolbar: Ad Blocker Pro Toolbar - {28BC2EC4-5EAD-45E1-9F9F-82CD5E293601} - C:\Program Files\3B Software\3B Ad Blocker Pro\AKToolbar.dll
O4 - HKLM\..\Run: [Windows Clean-Up Pro] C:\PROGRA~1\3BSOFT~1\WINDOW~2\WINDOWS CLEAN-UP PRO.Exe
O4 - HKLM\..\Run: [AdBlocker] C:\Program Files\3B Software\3B Ad Blocker Pro\AdBlocker.exe
O4 - HKLM\..\Run: [avast!] C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
O4 - HKLM\..\Run: [NVMixerTray] "C:\Program Files\NVIDIA Corporation\NvMixer\NVMixerTray.exe"
O4 - HKLM\..\Run: [LXSUPMON] C:\WINDOWS\system32\LXSUPMON.EXE RUN
O4 - HKLM\..\Run: [AVG7_CC] C:\PROGRA~1\Grisoft\AVG7\avgcc.exe /STARTUP
O4 - HKLM\..\Run: [ZoneAlarm Client] "C:\Program Files\Zone Labs\ZoneAlarm\zlclient.exe"
O4 - HKCU\..\Run: [msnmsgr] "C:\Program Files\MSN Messenger\msnmsgr.exe" /background
O4 - HKCU\..\Run: [ctfmon.exe] C:\WINDOWS\system32\ctfmon.exe
O4 - HKCU\..\Run: [Windows Registry Repair Pro] C:\Program Files\Windows Registry Repair Pro\RegistryRepairPro.exe 4
O4 - HKCU\..\Run: [Configuration de la C-BOX] C:\Program Files\Cegetel\C-BOX\Wizard\QuickAccess.exe
O8 - Extra context menu item: E&xporter vers Microsoft Excel - res://C:\PROGRA~1\MICROS~2\Office10\EXCEL.EXE/3000
O16 - DPF: {17492023-C23A-453E-A040-C7C580BBF700} (Windows Genuine Advantage Validation Tool) - http://download.microsoft.com/download/E/5/6/E5611B10-0D6D-4117-8430-A67417AA88CD/LegitCheckControl.cab
O16 - DPF: {5CA8D349-C6E7-11D4-8166-009027DF3BB2} (France Telecom MDDK ActiveX Control) - http://accueil.ava.serveur-ava.com/stkid_data/ocx/mDKid.cab
O17 - HKLM\System\CCS\Services\Tcpip\..\{66B2FFCF-426F-4E1D-A833-25A01B60132C}: NameServer = 86.64.145.140,84.103.237.140
O18 - Protocol: msnim - {828030A1-22C1-4009-854F-8E305202313F} - "C:\PROGRA~1\MSNMES~1\msgrapp.dll" (file missing)
O20 - AppInit_DLLs: C:\PROGRA~1\Google\GOOGLE~3\GOEC62~1.DLL
O20 - Winlogon Notify: WgaLogon - C:\WINDOWS\SYSTEM32\WgaLogon.dll
O23 - Service: avast! iAVS4 Control Service (aswUpdSv) - ALWIL Software - C:\Program Files\Alwil Software\Avast4\aswUpdSv.exe
O23 - Service: avast! Antivirus - ALWIL Software - C:\Program Files\Alwil Software\Avast4\ashServ.exe
O23 - Service: avast! Mail Scanner - Unknown owner - C:\Program Files\Alwil Software\Avast4\ashMaiSv.exe" /service (file missing)
O23 - Service: avast! Web Scanner - Unknown owner - C:\Program Files\Alwil Software\Avast4\ashWebSv.exe" /service (file missing)
O23 - Service: AVG7 Alert Manager Server (Avg7Alrt) - GRISOFT, s.r.o. - C:\PROGRA~1\Grisoft\AVG7\avgamsvr.exe
O23 - Service: AVG7 Update Service (Avg7UpdSvc) - GRISOFT, s.r.o. - C:\PROGRA~1\Grisoft\AVG7\avgupsvc.exe
O23 - Service: AVG E-mail Scanner (AVGEMS) - GRISOFT, s.r.o. - C:\PROGRA~1\Grisoft\AVG7\avgemc.exe
O23 - Service: Google Updater Service (gusvc) - Google - C:\Program Files\Google\Common\Google Updater\GoogleUpdaterService.exe
O23 - Service: LexBce Server (LexBceS) - Lexmark International, Inc. - C:\WINDOWS\system32\LEXBCES.EXE
O23 - Service: NVIDIA Driver Helper Service (NVSvc) - NVIDIA Corporation - C:\WINDOWS\system32\nvsvc32.exe
O23 - Service: StarWind iSCSI Service (StarWindService) - Rocket Division Software - C:\Program Files\Alcohol Soft\Alcohol 120\StarWind\StarWindService.exe
O23 - Service: TrueVector Internet Monitor (vsmon) - Zone Labs, LLC - C:\WINDOWS\system32\ZoneLabs\vsmon.exe