Virus ou pas?

Bonjour, j'ai mon PC depuis un an(MEDION IntelCore2Duo E6600 2,40GHZ 2G de ram VISTA édition familiale premium), il marchait sans aucun problème jusqu'à la semaine dernière.

Windows fut très long à se lancé(1/2heure environ), et une fois lancé il y avait des gros ralentissement assez aléatoires, et des programmes se bloquaient avec des erreurs type E/S 0xc0000185...

La dernière chose que j'avais installé était Direct X9.0c, mais c'était une semaine avant ça. J'ai lancé une analyse Bitdefender(qui a duré 14heures!) mais il n'a rien trouvé. J'ai aussi fait une analyse HIJACK:

Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 23:55:22, on 24/07/2008
Platform: Windows Vista SP1 (WinNT 6.00.1905)
MSIE: Internet Explorer v7.00 (7.00.6001.18000)
Boot mode: Normal

Running processes:
C:\Windows\Explorer.EXE
C:\Program Files\BitDefender\BitDefender 2008\bdagent.exe
C:\Program Files\Java\jre1.6.0_04\bin\jusched.exe
C:\Windows\ehome\ehtray.exe
C:\Windows\system32\taskeng.exe
C:\Windows\ehome\ehmsas.exe
C:\Program Files\BitDefender\BitDefender 2008\bdagent.exe
C:\Windows\System32\wsqmcons.exe
C:\Windows\system32\wbem\unsecapp.exe
C:\Windows\system32\Dwm.exe
C:\Program Files\Internet Explorer\IEUser.exe
C:\Windows\system32\rundll32.exe
C:\Program Files\Trend Micro\HijackThis\HijackThis.exe

R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = https://news.google.com/topstories?hl=fr&gl=FR&ceid=FR:fr
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://www.carrefour.fr
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Search_URL = https://www.bing.com/?toHttps=1&redig=5FC791212101479BAFBE1A679848B1AF
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 =
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,CustomizeSearch =
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Window Title = Internet Explorer avec Club-Internet
R1 - HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings,ProxyOverride = 127.0.0.1;*.local
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName =
O1 - Hosts: ::1 localhost
O2 - BHO: AcroIEHlprObj Class - {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\jre1.6.0_04\bin\ssv.dll
O2 - BHO: (no name) - {7E853D72-626A-48EC-A868-BA8D5E23E045} - (no file)
O2 - BHO: Google Toolbar Helper - {AA58ED58-01DD-4d91-8333-CF10577473F7} - c:\program files\google\googletoolbar1.dll
O3 - Toolbar: &Google - {2318C2B1-4965-11d4-9B18-009027A5CD4F} - c:\program files\google\googletoolbar1.dll
O3 - Toolbar: BitDefender Toolbar - {381FFDE8-2394-4f90-B10D-FC6124A40F8C} - C:\Program Files\BitDefender\BitDefender 2008\IEToolbar.dll
O4 - HKLM\..\Run: [Windows Defender] %ProgramFiles%\Windows Defender\MSASCui.exe -hide
O4 - HKLM\..\Run: [BDAgent] "C:\Program Files\BitDefender\BitDefender 2008\bdagent.exe"
O4 - HKLM\..\Run: [SunJavaUpdateSched] "C:\Program Files\Java\jre1.6.0_04\bin\jusched.exe"
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: [ehTray.exe] C:\Windows\ehome\ehTray.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) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.6.0_04\bin\ssv.dll
O9 - Extra 'Tools' menuitem: Console Java (Sun) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.6.0_04\bin\ssv.dll
O13 - Gopher Prefix:
O16 - DPF: {D27CDB6E-AE6D-11CF-96B8-444553540000} (Shockwave Flash Object) - http://fpdownload2.macromedia.com/get/shockwave/cabs/flash/swflash.cab
O20 - AppInit_DLLs: C:\PROGRA~1\Google\GOOGLE~2\GOEC62~1.DLL
O23 - Service: Google Desktop Manager 5.1.709.19590 (GoogleDesktopManager-091907-194040) - Google - C:\Program Files\Google\Google Desktop Search\GoogleDesktop.exe
O23 - Service: Google Updater Service (gusvc) - Google - C:\Program Files\Google\Common\Google Updater\GoogleUpdaterService.exe
O23 - Service: LightScribeService Direct Disc Labeling Service (LightScribeService) - Hewlett-Packard Company - C:\Program Files\Common Files\LightScribe\LSSrvc.exe
O23 - Service: BitDefender Desktop Update Service (LIVESRV) - BitDefender SRL - C:\Program Files\Common Files\BitDefender\BitDefender Update Service\livesrv.exe
O23 - Service: NBService - Nero AG - C:\Program Files\Nero\Nero 7\Nero BackItUp\NBService.exe
O23 - Service: NMIndexingService - Nero AG - C:\Program Files\Common Files\Ahead\Lib\NMIndexingService.exe
O23 - Service: NVIDIA Display Driver Service (nvsvc) - NVIDIA Corporation - C:\Windows\system32\nvvsvc.exe
O23 - Service: BitDefender Virus Shield (VSSERV) - BitDefender S.R.L. - C:\Program Files\BitDefender\BitDefender 2008\vsserv.exe
O23 - Service: BitDefender Communicator (XCOMM) - BitDefender - C:\Program Files\Common Files\BitDefender\BitDefender Communicator\xcommsvr.exe