Mon pc rame

Bonjour,
Voilà je vais essayer d'être bref et précis,...Depuis quelque temps mon ordi rame grave j'ai passé un coup de balai avec ccleaner et fais une défragmentation du disque dur, mais rien, je pense que j'ai un virus virulent genre allien, si quelqu'un peut m'aider ça serait trop sympas.
merci à tous.
voilà le rapport hijackthis.

Scan saved at 15:45:44, on 18/02/2010
Platform: Windows Vista SP2 (WinNT 6.00.1906)
MSIE: Internet Explorer v8.00 (8.00.6001.18882)
Boot mode: Normal

Running processes:
C:\Windows\system32\Dwm.exe
C:\Windows\Explorer.EXE
C:\Program Files\Windows Defender\MSASCui.exe
C:\Windows\RtHDVCpl.exe
C:\Program Files\Alwil Software\Avast4\ashDisp.exe
C:\Program Files\Common Files\Java\Java Update\jusched.exe
C:\Windows\WindowsMobile\wmdc.exe
C:\Windows\system32\taskeng.exe
C:\Windows\system32\wbem\unsecapp.exe
C:\Program Files\Mozilla Firefox\firefox.exe
C:\Users\benouali\Desktop\HiJackThis.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Bar = https://www.bing.com/?toHttps=1&redig=5FC791212101479BAFBE1A679848B1AF
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = https://www.google.fr/?gws_rd=ssl
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,SearchAssistant =
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,CustomizeSearch =
R3 - URLSearchHook: UrlSearchHook Class - {00000000-6E41-4FD3-8538-502F5495E5FC} - C:\Program Files\Ask.com\GenericAskToolbar.dll (file missing)
O2 - BHO: AcroIEHelperStub - {18DF081C-E8AD-4283-A596-FA578C2EBDC3} - C:\Program Files\Common Files\Adobe\Acrobat\ActiveX\AcroIEHelperShim.dll
O2 - BHO: Search Helper - {6EBF7485-159F-4bff-A14F-B9E3AAC4465B} - C:\Program Files\Microsoft\Search Enhancement Pack\Search Helper\SEPsearchhelperie.dll
O2 - BHO: Programme d'aide de l'Assistant de connexion Windows Live ID - {9030D464-4C02-4ABF-8ECC-5164760863C6} - C:\Program Files\Common Files\Microsoft Shared\Windows Live\WindowsLiveLogin.dll
O2 - BHO: Java(tm) Plug-In 2 SSV Helper - {DBC80044-A445-435b-BC74-9C25C1C588A9} - C:\Program Files\Java\jre6\bin\jp2ssv.dll
O2 - BHO: Windows Live Toolbar Helper - {E15A8DC0-8516-42A1-81EA-DC94EC1ACF10} - C:\Program Files\Windows Live\Toolbar\wltcore.dll
O3 - Toolbar: &Windows Live Toolbar - {21FA44EF-376D-4D53-9B0F-8A89D3229068} - C:\Program Files\Windows Live\Toolbar\wltcore.dll
O3 - Toolbar: (no name) - {D4027C7F-154A-4066-A1AD-4243D8127440} - (no file)
O4 - HKLM\..\Run: [Windows Defender] %ProgramFiles%\Windows Defender\MSASCui.exe -hide
O4 - HKLM\..\Run: [RtHDVCpl] RtHDVCpl.exe
O4 - HKLM\..\Run: [NvCplDaemon] RUNDLL32.EXE C:\Windows\system32\NvCpl.dll,NvStartup
O4 - HKLM\..\Run: [avast!] C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
O4 - HKLM\..\Run: [SunJavaUpdateSched] "C:\Program Files\Common Files\Java\Java Update\jusched.exe"
O4 - HKLM\..\Run: [Windows Mobile Device Center] %windir%\WindowsMobile\wmdc.exe
O4 - Startup: LimeWire On Startup.lnk = C:\Program Files\LimeWire\LimeWire.exe
O9 - Extra button: Ajout Direct - {219C3416-8CB2-491a-A3C7-D9FCDDC9D600} - C:\Program Files\Windows Live\Writer\WriterBrowserExtension.dll
O9 - Extra 'Tools' menuitem: &Ajout Direct dans Windows Live Writer - {219C3416-8CB2-491a-A3C7-D9FCDDC9D600} - C:\Program Files\Windows Live\Writer\WriterBrowserExtension.dll
O9 - Extra button: Envoyer à OneNote - {2670000A-7350-4f3c-8081-5663EE0C6C49} - C:\PROGRA~1\MICROS~2\Office12\ONBttnIE.dll
O9 - Extra 'Tools' menuitem: &Envoyer à OneNote - {2670000A-7350-4f3c-8081-5663EE0C6C49} - C:\PROGRA~1\MICROS~2\Office12\ONBttnIE.dll
O9 - Extra button: @C:\Windows\WindowsMobile\INetRepl.dll,-222 - {2EAF5BB1-070F-11D3-9307-00C04FAE2D4F} - C:\Windows\WindowsMobile\INetRepl.dll
O9 - Extra button: (no name) - {2EAF5BB2-070F-11D3-9307-00C04FAE2D4F} - C:\Windows\WindowsMobile\INetRepl.dll
O9 - Extra 'Tools' menuitem: @C:\Windows\WindowsMobile\INetRepl.dll,-223 - {2EAF5BB2-070F-11D3-9307-00C04FAE2D4F} - C:\Windows\WindowsMobile\INetRepl.dll
O9 - Extra button: Research - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - C:\PROGRA~1\MICROS~2\Office12\REFIEBAR.DLL
O13 - Gopher Prefix:
O20 - AppInit_DLLs: C:\Windows\System32\esent32.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 - ALWIL Software - C:\Program Files\Alwil Software\Avast4\ashMaiSv.exe
O23 - Service: avast! Web Scanner - ALWIL Software - C:\Program Files\Alwil Software\Avast4\ashWebSv.exe
O23 - Service: Service Google Update (gupdate1ca574acf3ad244) (gupdate1ca574acf3ad244) - Google Inc. - C:\Program Files\Google\Update\GoogleUpdate.exe
O23 - Service: LightScribeService Direct Disc Labeling Service (LightScribeService) - Hewlett-Packard Company - C:\Program Files\Common Files\LightScribe\LSSrvc.exe
O23 - Service: Process Monitor (LVPrcSrv) - Logitech Inc. - C:\Program Files\Common Files\LogiShrd\LVMVFM\LVPrcSrv.exe
O23 - Service: Ma-Config Service (maconfservice) - CybelSoft - C:\Program Files\ma-config.com\maconfservice.exe
O23 - Service: Nero BackItUp Scheduler 3 - Nero AG - C:\Program Files\Nero\Nero8\Nero BackItUp\NBService.exe
O23 - Service: NVIDIA Display Driver Service (NVSvc) - NVIDIA Corporation - C:\Windows\system32\nvvsvc.exe