UC à 100%, PC extremement lent (Vista)

Bonjour,
Depuis quelques temps j'ai un problème de grosse lenteur avec mon pc, il met environ 15-25 minutes à démarrer, l'UC est utilisé à 100% au démarrage (alors que j'ai presque rien qui se lance au démarrage normalement) et la mémoire est utilisé à 60%.
Et le problème ne se fait pas que au démarrage, quelquefois il se bloque carrement pendant 5 minutes avant que tout redevienne normal.
Je ne comprends plus rien d'autant plus que j'ai fait plusieurs tests antivirus sans succès...
Voici le log Hijackthis:

Logfile of HijackThis v1.99.1
Scan saved at 22:09:40, on 07/08/2007
Platform: Unknown Windows (WinNT 6.00.1904)
MSIE: Internet Explorer v7.00 (7.00.6000.16473)

Running processes:
C:\Windows\system32\taskeng.exe
C:\Windows\system32\Dwm.exe
C:\Windows\Explorer.EXE
C:\Program Files\Windows Defender\MSASCui.exe
C:\Program Files\Java\jre1.6.0_02\bin\jusched.exe
C:\Program Files\Common Files\Real\Update_OB\realsched.exe
C:\Program Files\QuickTime\QTTask.exe
C:\Program Files\iTunes\iTunesHelper.exe
C:\Program Files\Alwil Software\Avast4\ashDisp.exe
C:\Program Files\DAP\DAP.exe
C:\Program Files\Windows Sidebar\sidebar.exe
C:\Program Files\Google\GoogleToolbarNotifier\1.2.1128.5462\GoogleToolbarNotifier.exe
C:\Program Files\DAEMON Tools\daemon.exe
C:\Program Files\Windows Media Player\wmpnscfg.exe
C:\Windows\System32\rundll32.exe
C:\Windows\system32\Taskmgr.exe
C:\Program Files\Internet Explorer\iexplore.exe
C:\Program Files\Common Files\Microsoft Shared\Windows Live\WLLoginProxy.exe
C:\Program Files\WinRAR\WinRAR.exe
C:\Users\CDRAC~1\AppData\Local\Temp\Rar$EX00.228\HijackThis.exe

R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://www.google.fr/
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://go.microsoft.com/fwlink/?LinkId=69157
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Search_URL = http://go.microsoft.com/fwlink/?LinkId=54896
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Page = http://go.microsoft.com/fwlink/?LinkId=54896
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Start Page = http://go.microsoft.com/fwlink/?LinkId=69157
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,SearchAssistant =
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,CustomizeSearch =
R1 - HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings,ProxyOverride = *.local
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName =
O1 - Hosts: ::1 localhost
O2 - BHO: Aide pour le lien d'Adobe PDF Reader - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Common Files\Adobe\Acrobat\ActiveX\AcroIEHelper.dll
O2 - BHO: SSVHelper Class - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Program Files\Java\jre1.6.0_02\bin\ssv.dll
O2 - BHO: (no name) - {7E853D72-626A-48EC-A868-BA8D5E23E045} - (no file)
O2 - BHO: Windows Live Sign-in Helper - {9030D464-4C02-4ABF-8ECC-5164760863C6} - C:\Program Files\Common Files\Microsoft Shared\Windows Live\WindowsLiveLogin.dll
O2 - BHO: Google Toolbar Helper - {AA58ED58-01DD-4d91-8333-CF10577473F7} - c:\program files\google\googletoolbar2.dll
O3 - Toolbar: &Google - {2318C2B1-4965-11d4-9B18-009027A5CD4F} - c:\program files\google\googletoolbar2.dll
O4 - HKLM\..\Run: [Windows Defender] %ProgramFiles%\Windows Defender\MSASCui.exe -hide
O4 - HKLM\..\Run: [NeroFilterCheck] C:\Program Files\Common Files\Ahead\Lib\NeroCheck.exe
O4 - HKLM\..\Run: [SunJavaUpdateSched] "C:\Program Files\Java\jre1.6.0_02\bin\jusched.exe"
O4 - HKLM\..\Run: [TkBellExe] "C:\Program Files\Common Files\Real\Update_OB\realsched.exe" -osboot
O4 - HKLM\..\Run: [Adobe Reader Speed Launcher] "C:\Program Files\Adobe\Reader 8.0\Reader\Reader_sl.exe"
O4 - HKLM\..\Run: [NvSvc] RUNDLL32.EXE C:\Windows\system32\nvsvc.dll,nvsvcStart
O4 - HKLM\..\Run: [NvCplDaemon] RUNDLL32.EXE C:\Windows\system32\NvCpl.dll,NvStartup
O4 - HKLM\..\Run: [NvMediaCenter] RUNDLL32.EXE C:\Windows\system32\NvMcTray.dll,NvTaskbarInit
O4 - HKLM\..\Run: [QuickTime Task] "C:\Program Files\QuickTime\QTTask.exe" -atboottime
O4 - HKLM\..\Run: [iTunesHelper] "C:\Program Files\iTunes\iTunesHelper.exe"
O4 - HKLM\..\Run: [MonAppli] C:\Users\CDRAC~1\AppData\Local\Temp\IXP017.TMP\isys32.exe
O4 - HKLM\..\Run: [avast!] C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
O4 - HKLM\..\Run: [DownloadAccelerator] "C:\Program Files\DAP\DAP.EXE" /STARTUP
O4 - HKCU\..\Run: [Sidebar] C:\Program Files\Windows Sidebar\sidebar.exe /autoRun
O4 - HKCU\..\Run: [swg] C:\Program Files\Google\GoogleToolbarNotifier\1.2.1128.5462\GoogleToolbarNotifier.exe
O4 - HKCU\..\Run: [DAEMON Tools] "C:\Program Files\DAEMON Tools\daemon.exe" -lang 1033
O4 - HKCU\..\Run: [WMPNSCFG] C:\Program Files\Windows Media Player\WMPNSCFG.exe
O4 - Startup: Adobe Gamma.lnk = C:\Program Files\Common Files\Adobe\Calibration\Adobe Gamma Loader.exe
O8 - Extra context menu item: &Clean Traces - C:\Program Files\DAP\Privacy Package\dapcleanerie.htm
O8 - Extra context menu item: &Download with &DAP - C:\Program Files\DAP\dapextie.htm
O8 - Extra context menu item: Download &all with DAP - C:\Program Files\DAP\dapextie2.htm
O8 - Extra context menu item: Download FLV video content with IDM - C:\Program Files\Internet Download Manager\IEGetVL.htm
O8 - Extra context menu item: E&xporter vers Microsoft Excel - res://C:\PROGRA~1\MICROS~2\Office12\EXCEL.EXE/3000
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.6.0_02\bin\ssv.dll
O9 - Extra 'Tools' menuitem: Console Java (Sun) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.6.0_02\bin\ssv.dll
O9 - Extra button: Research - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - C:\PROGRA~1\MICROS~2\Office12\REFIEBAR.DLL
O10 - Unknown file in Winsock LSP: c:\windows\system32\nlaapi.dll
O10 - Unknown file in Winsock LSP: c:\windows\system32\napinsp.dll
O10 - Unknown file in Winsock LSP: c:\program files\bonjour\mdnsnsp.dll
O11 - Options group: [INTERNATIONAL] International*
O13 - Gopher Prefix:
O16 - DPF: {4C833081-D026-4FF8-968F-7EAB660D2FBA} (TVAnts ActiveX Control) - http://download.tvants.com/pub/tva [...] tvants.cab
O18 - Protocol: livecall - {828030A1-22C1-4009-854F-8E305202313F} - C:\PROGRA~1\MSNMES~1\MSGRAP~1.DLL
O18 - Protocol: ms-help - {314111C7-A502-11D2-BBCA-00C04F8EC294} - C:\Program Files\Common Files\Microsoft Shared\Help\hxds.dll
O18 - Protocol: msnim - {828030A1-22C1-4009-854F-8E305202313F} - C:\PROGRA~1\MSNMES~1\MSGRAP~1.DLL
O18 - Filter hijack: text/xml - {807563E5-5146-11D5-A672-00B0D022E945} - C:\PROGRA~1\COMMON~1\MICROS~1\OFFICE12\MSOXMLMF.DLL
O23 - Service: Adobe LM Service - Adobe Systems - C:\Program Files\Common Files\Adobe Systems Shared\Service\Adobelmsvc.exe
O23 - Service: Apple Mobile Device - Apple, Inc. - C:\Program Files\Common Files\Apple\Mobile Device Support\bin\AppleMobileDeviceService.exe
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: ##Id_String1.6844F930_1628_4223_B5CC_5BB94B879762## (Bonjour Service) - Apple Computer, Inc. - C:\Program Files\Bonjour\mDNSResponder.exe
O23 - Service: @%SystemRoot%\ehome\ehstart.dll,-101 (ehstart) - Unknown owner - %windir%\system32\svchost.exe (file missing)
O23 - Service: FLEXnet Licensing Service - Macrovision Europe Ltd. - C:\Program Files\Common Files\Macrovision Shared\FLEXnet Publisher\FNPLicensingService.exe
O23 - Service: Google Updater Service (gusvc) - Google - C:\Program Files\Google\Common\Google Updater\GoogleUpdaterService.exe
O23 - Service: @%windir%\system32\inetsrv\iisres.dll,-30007 (IISADMIN) - Unknown owner - %windir%\system32\inetsrv\inetinfo.exe (file missing)
O23 - Service: Service de l'iPod (iPod Service) - Apple Inc. - C:\Program Files\iPod\bin\iPodService.exe
O23 - Service: @%windir%\system32\inetsrv\iisres.dll,-30005 (MSFTPSVC) - Unknown owner - %windir%\system32\inetsrv\inetinfo.exe (file missing)
O23 - Service: NBService - Nero AG - C:\Program Files\Nero\Nero 7\Nero BackItUp\NBService.exe
O23 - Service: @%SystemRoot%\system32\qwave.dll,-1 (QWAVE) - Unknown owner - %windir%\system32\svchost.exe (file missing)
O23 - Service: @%SystemRoot%\system32\seclogon.dll,-7001 (seclogon) - Unknown owner - %windir%\system32\svchost.exe (file missing)
O23 - Service: StarWind iSCSI Service (StarWindService) - Rocket Division Software - C:\Program Files\Alcohol Soft\Alcohol 120\StarWind\StarWindService.exe
O23 - Service: @%windir%\system32\inetsrv\iisres.dll,-30003 (W3SVC) - Unknown owner - %windir%\system32\svchost.exe (file missing)
O23 - Service: @%windir%\system32\inetsrv\iisres.dll,-30001 (WAS) - Unknown owner - %windir%\system32\svchost.exe (file missing)
O23 - Service: @%ProgramFiles%\Windows Media Player\wmpnetwk.exe,-101 (WMPNetworkSvc) - Unknown owner - %ProgramFiles%\Windows Media Player\wmpnetwk.exe (file missing)
O23 - Service: @%windir%\system32\inetsrv\iisres.dll,-20001 (WMSvc) - Unknown owner - %windir%\system32\inetsrv\wmsvc.exe (file missing)


En espérant que quelqu'un pourra m'éclairer svp !!!
Merci d'avance