Vista se bloque!

Bonjour,
J'ai vista depuis qques mois déjà, et depuis 1 semaine, il se bloque comme ça, sans crier gare, sans message d"erreur; Ctrl+Alt+Suppr ne fonctionne même pas, tout est figé dans le marbre! Seule solution, faire un boot sauvage du pc! J'enrage!
Je mets plus bas le rapport que j'ai fait avec HijackThis! Si qqun pouvait jeter un coup d'oeil et me dire ce qui ne vas pas!
Ma config : vita premium/p4 d820c/Geforce nx7100gs/1024 mo ram.
Petite précision : mon anti-virus Avast est en protection résidente et bitdefender en scan ponctuel! Dc, pas d'interférence normalement entre les 2!
Voilà et merci d'avance!

Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 17:09:41, on 03/11/2007
Platform: Windows Vista (WinNT 6.00.1904)
MSIE: Internet Explorer v7.00 (7.00.6000.16546)
Boot mode: Normal

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\Alwil Software\Avast4\ashDisp.exe
C:\Windows\System32\rundll32.exe
C:\Program Files\Windows Sidebar\sidebar.exe
C:\Windows\ehome\ehtray.exe
C:\Program Files\RocketDock\RocketDock.exe
C:\Program Files\Windows Media Player\wmpnscfg.exe
C:\Windows\ehome\ehmsas.exe
C:\Windows\System32\rundll32.exe
C:\Windows\system32\wbem\unsecapp.exe
C:\PROGRA~1\MOZILLA FIREFOX\FIREFOX.EXE
C:\HiJackThis\HijackThis.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Bar = http://g.msn.fr/0SEFRFR/SAOS01?FORM=TOOLBR
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Page = http://g.msn.fr/0SEFRFR/SAOS01?FORM=TOOLBR
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://go.microsoft.com/fwlink/?LinkId=69157
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\Internet Explorer\SearchURL,(Default) = http://g.msn.fr/0SEFRFR/SAOS01?FORM=TOOLBR
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName =
R3 - URLSearchHook: Search Class - {08C06D61-F1F3-4799-86F8-BE1A89362C85} - C:\Program Files\OrangeHSS\SearchURLHook\SearchPageURL.dll
O1 - Hosts: ::1 localhost
O2 - BHO: Spybot-S&D IE Protection - {53707962-6F74-2D53-2644-206D7942484F} - C:\PROGRA~1\SPYBOT~1\SDHelper.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: Windows Live Toolbar Helper - {BDBD1DAD-C946-4A17-ADC1-64B5B4FF55D0} - C:\Program Files\Windows Live Toolbar\msntb.dll
O3 - Toolbar: Windows Live Toolbar - {BDAD1DAD-C946-4A17-ADC1-64B5B4FF55D0} - C:\Program Files\Windows Live Toolbar\msntb.dll
O4 - HKLM\..\Run: [Windows Defender] %ProgramFiles%\Windows Defender\MSASCui.exe -hide
O4 - HKLM\..\Run: [avast!] C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.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 - HKCU\..\Run: [Sidebar] C:\Program Files\Windows Sidebar\sidebar.exe /autoRun
O4 - HKCU\..\Run: [ehTray.exe] C:\Windows\ehome\ehTray.exe
O4 - HKCU\..\Run: [RocketDock] "C:\Program Files\RocketDock\RocketDock.exe"
O4 - HKCU\..\Run: [WMPNSCFG] C:\Program Files\Windows Media Player\WMPNSCFG.exe
O4 - HKUS\S-1-5-19\..\Run: [Sidebar] %ProgramFiles%\Windows Sidebar\Sidebar.exe /detectMem (User 'SERVICE LOCAL')
O4 - HKUS\S-1-5-19\..\Run: [WindowsWelcomeCenter] rundll32.exe oobefldr.dll,ShowWelcomeCenter (User 'SERVICE LOCAL')
O4 - HKUS\S-1-5-20\..\Run: [Sidebar] %ProgramFiles%\Windows Sidebar\Sidebar.exe /detectMem (User 'SERVICE RÉSEAU')
O9 - Extra button: (no name) - {DFB852A3-47F8-48C4-A200-58CAB36FD2A2} - C:\PROGRA~1\SPYBOT~1\SDHelper.dll
O9 - Extra 'Tools' menuitem: Spybot - Search & Destroy Configuration - {DFB852A3-47F8-48C4-A200-58CAB36FD2A2} - C:\PROGRA~1\SPYBOT~1\SDHelper.dll
O13 - Gopher Prefix:
O16 - DPF: {67DABFBF-D0AB-41FA-9C46-CC0F21721616} (DivXBrowserPlugin Object) - http://download.divx.com/player/DivXBrowserPlugin.cab
O23 - Service: Ad-Aware 2007 Service (aawservice) - Lavasoft AB - C:\Program Files\Lavasoft\Ad-Aware 2007\aawservice.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 - 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: BitDefender Scan Server (bdss) - Unknown owner - C:\Program Files\Common Files\Softwin\BitDefender Scan Server\bdss.exe
O23 - Service: France Telecom Routing Table Service (FTRTSVC) - France Telecom SA - C:\PROGRA~1\COMMON~1\France Telecom\Shared Modules\FTRTSVC\0\FTRTSVC.exe
O23 - Service: BitDefender Desktop Update Service (LIVESRV) - SOFTWIN S.R.L. - C:\Program Files\Common Files\Softwin\BitDefender Update Service\livesrv.exe
O23 - Service: BitDefender Virus Shield (VSSERV) - SOFTWIN S.R.L. - C:\Program Files\Softwin\BitDefender10\vsserv.exe
O23 - Service: BitDefender Communicator (XCOMM) - SOFTWIN S.R.L - C:\Program Files\Common Files\Softwin\BitDefender Communicator\xcommsvr.exe
End of file - 5464 bytes

Configuration: Windows Vista
Firefox 2.0.0.9