J'AI UN VIRUS?

Bonjour,
mon PC ne démarre plus normalement, j'ai un fond d'écran et c'est tout, plus d'icone, clic droit de la souris pas valide.
En fait c'est explorer.exe qui ne démarre pas ou qui est bloqué...
le fait de faire Alt+Ctrl+Sup puis dans EXECUTE je tape explorer.exe et mon bureau devient normal.
que dois je faire.
merci d'avance pour de l'aide j'y suis depuis une semaine, j'en dors plus...
rapport hijackthis:

Logfile of HijackThis v1.99.1
Scan saved at 14:23:23, on 08/03/2008
Platform: Windows XP SP2 (WinNT 5.01.2600)
MSIE: Internet Explorer v7.00 (7.00.6000.16608)

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:\Program Files\Fichiers communs\Microsoft Shared\VS7Debug\mdm.exe
C:\Program Files\Canon\MultiPASS4\MPSERVIC.EXE
C:\PROGRA~1\TRENDM~1\INTERN~1\PcCtlCom.exe
C:\WINDOWS\system32\slserv.exe
C:\WINDOWS\System32\svchost.exe
C:\PROGRA~1\TRENDM~1\INTERN~1\Tmntsrv.exe
C:\PROGRA~1\TRENDM~1\INTERN~1\TmPfw.exe
C:\PROGRA~1\TRENDM~1\INTERN~1\tmproxy.exe
C:\Program Files\Virtual CD v4 SDK\system\vcssecs.exe
C:\Program Files\Blue Coat K9 Web Protection\k9filter.exe
C:\PROGRA~1\TRENDM~1\INTERN~1\PcScnSrv.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\explorer.exe
C:\Program Files\Virtual CD v4 SDK\system\vcsplay.exe
C:\Program Files\Fichiers communs\Real\Update_OB\realsched.exe
C:\Program Files\CyberLink\PowerDVD\PDVDServ.exe
C:\Program Files\QuickTime\qttask.exe
C:\Program Files\Trend Micro\Internet Security 2007\pccguide.exe
C:\Program Files\ScanSoft\OmniPageSE\opware32.exe
C:\PROGRA~1\Canon\MULTIP~1\MPTBox.exe
C:\Program Files\SlySoft\CloneCD\CloneCDTray.exe
C:\Program Files\Neuf\Kit\WiFi\9wifi.exe
C:\ATI Technologies\ATI Control Panel\atiptaxx.exe
C:\apps\ABoard\ABoard.exe
C:\WINDOWS\wt\updater\wcmdmgr.exe
C:\WINDOWS\system32\ctfmon.exe
C:\apps\ABoard\AOSD.exe
C:\Program Files\Microsoft Office\Office10\msoffice.exe
C:\Program Files\Canon\MultiPASS4\MPDBMgr.exe
C:\Program Files\Internet Explorer\iexplore.exe
C:\Program Files\Fichiers communs\Microsoft Shared\Windows Live\WLLoginProxy.exe
C:\hijackthis\HijackThis.exe

R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = https://www.google.fr/?gws_rd=ssl
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = https://www.msn.com/fr-fr/?ocid=iehp
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Search_URL = https://actus.sfr.fr
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Page = https://www.bing.com/?toHttps=1&redig=5FC791212101479BAFBE1A679848B1AF
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Start Page = https://www.msn.com/fr-fr/?ocid=iehp
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,SearchAssistant = https://actus.sfr.fr
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Window Title = Packard Bell
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Liens
R3 - URLSearchHook: &Yahoo! Toolbar - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - (no file)
O2 - BHO: Adobe PDF Reader Link Helper - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Adobe\Acrobat 7.0\ActiveX\AcroIEHelper.dll
O2 - BHO: SSVHelper Class - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Program Files\Java\jre1.5.0_13\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\Fichiers communs\Microsoft Shared\Windows Live\WindowsLiveLogin.dll
O4 - HKLM\..\Run: [VCSPlayer] "C:\Program Files\Virtual CD v4 SDK\system\vcsplay.exe"
O4 - HKLM\..\Run: [TkBellExe] "C:\Program Files\Fichiers communs\Real\Update_OB\realsched.exe" -osboot
O4 - HKLM\..\Run: [RemoteControl] "C:\Program Files\CyberLink\PowerDVD\PDVDServ.exe"
O4 - HKLM\..\Run: [QuickTime Task] "C:\Program Files\QuickTime\qttask.exe" -atboottime
O4 - HKLM\..\Run: [PinnacleDriverCheck] C:\WINDOWS\System32\PSDrvCheck.exe -CheckReg
O4 - HKLM\..\Run: [pccguide.exe] "C:\Program Files\Trend Micro\Internet Security 2007\pccguide.exe"
O4 - HKLM\..\Run: [Omnipage] C:\Program Files\ScanSoft\OmniPageSE\opware32.exe
O4 - HKLM\..\Run: [NeroFilterCheck] C:\WINDOWS\system32\NeroCheck.exe
O4 - HKLM\..\Run: [MPTBox] C:\PROGRA~1\Canon\MULTIP~1\MPTBox.exe
O4 - HKLM\..\Run: [CloneCDTray] "C:\Program Files\SlySoft\CloneCD\CloneCDTray.exe" /s
O4 - HKLM\..\Run: [Autoconfigurateur WiFi Neuf] C:\Program Files\Neuf\Kit\WiFi\9wifi.exe
O4 - HKLM\..\Run: [ATIPTA] C:\ATI Technologies\ATI Control Panel\atiptaxx.exe
O4 - HKLM\..\Run: [ATIModeChange] Ati2mdxx.exe
O4 - HKLM\..\Run: [ACTIVBOARD] c:\apps\ABoard\ABoard.exe
O4 - HKLM\..\Run: [CleanEasyImg] c:\apps\easydvd\cleanall.exe
O4 - HKLM\..\Run: [wcmdmgr] C:\WINDOWS\wt\updater\wcmdmgrl.exe -launch
O4 - HKCU\..\Run: [ctfmon.exe] C:\WINDOWS\system32\ctfmon.exe
O4 - Global Startup: Microsoft Office.lnk = C:\Program Files\Microsoft Office\Office10\OSA.EXE
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.5.0_13\bin\ssv.dll
O9 - Extra 'Tools' menuitem: Console Java (Sun) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.5.0_13\bin\ssv.dll
O9 - Extra button: Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\msmsgs.exe
O9 - Extra 'Tools' menuitem: Windows Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\msmsgs.exe
O11 - Options group: [INTERNATIONAL] International*
O14 - IERESET.INF: START_PAGE_URL=file://C:\APPS\IE\offline\fr.htm
O16 - DPF: {27527D31-447B-11D5-A46E-0001023B4289} (CoGSManager Class) - http://gamingzone.ubisoft.com/dev/packages/GSManager.cab
O16 - DPF: {67DABFBF-D0AB-41FA-9C46-CC0F21721616} (DivXBrowserPlugin Object) - http://download.divx.com/player/DivXBrowserPlugin.cab
O16 - DPF: {6E32070A-766D-4EE6-879C-DC1FA91D2FC3} (MUWebControl Class) - http://update.microsoft.com/...
O16 - DPF: {C3F79A2B-B9B4-4A66-B012-3EE46475B072} (MessengerStatsClient Class) - http://messenger.zone.msn.com/binary/MessengerStatsPAClient.cab56907.cab
O16 - DPF: {D27CDB6E-AE6D-11CF-96B8-444553540000} (Shockwave Flash Object) - http://fpdownload2.macromedia.com/get/shockwave/cabs/flash/swflash.cab
O18 - Protocol: livecall - {828030A1-22C1-4009-854F-8E305202313F} - C:\PROGRA~1\MSNMES~1\MSGRAP~1.DLL
O18 - Protocol: msnim - {828030A1-22C1-4009-854F-8E305202313F} - C:\PROGRA~1\MSNMES~1\MSGRAP~1.DLL
O20 - Winlogon Notify: WgaLogon - C:\WINDOWS\SYSTEM32\WgaLogon.dll
O21 - SSODL: WPDShServiceObj - {AAA288BA-9A4C-45B0-95D7-94D524869DB5} - C:\WINDOWS\system32\WPDShServiceObj.dll
O23 - Service: ATI Smart - Unknown owner - C:\WINDOWS\system32\ati2sgag.exe
O23 - Service: InstallDriver Table Manager (IDriverT) - Macrovision Corporation - C:\Program Files\Fichiers communs\InstallShield\Driver\1050\Intel 32\IDriverT.exe
O23 - Service: MpService - Canon Inc. - C:\Program Files\Canon\MultiPASS4\MPSERVIC.EXE
O23 - Service: Trend Micro Central Control Component (PcCtlCom) - Trend Micro Inc. - C:\PROGRA~1\TRENDM~1\INTERN~1\PcCtlCom.exe
O23 - Service: Protection Trend Micro contre les programmes espions (PcScnSrv) - Trend Micro Inc. - C:\PROGRA~1\TRENDM~1\INTERN~1\PcScnSrv.exe
O23 - Service: SmartLinkService (SLService) - - C:\WINDOWS\SYSTEM32\slserv.exe
O23 - Service: Trend Micro Real-time Service (Tmntsrv) - Trend Micro Inc. - C:\PROGRA~1\TRENDM~1\INTERN~1\Tmntsrv.exe
O23 - Service: Trend Micro Personal Firewall (TmPfw) - Trend Micro Inc. - C:\PROGRA~1\TRENDM~1\INTERN~1\TmPfw.exe
O23 - Service: Trend Micro Proxy Service (tmproxy) - Trend Micro Inc. - C:\PROGRA~1\TRENDM~1\INTERN~1\tmproxy.exe
O23 - Service: Virtual CD v4 Security service (SDK - Version) (VCSSecS) - H+H Software GmbH - C:\Program Files\Virtual CD v4 SDK\system\vcssecs.exe
O23 - Service: Blue Coat K9 Web Protection (WebFilter) - Unknown owner - C:\Program Files\Blue Coat K9 Web Protection\k9filter.exe