Redémarrage intempestif de Windows

Bonjour à tous,

Depuis qqes jours, je fais face à 1 pb assez énervant avec mon PC : il redémarre sans prévenir pendant l'éxécution d'1 programme, ou pendant le lancement d'un nouveau prog.
J'ai passé mon ordi au crible (Norton, Lavasoft, A-Squared), mais rien n'y fait !
voici le résultat de Hijackthis,

en espérant vraiment que qqun puisse faire qqchose pour moi...

Merci par avance pour votre aide / vos conseils / etc.

Funky Frunz... pas très funky en ce moment :-(

Logfile of HijackThis v1.99.1
Scan saved at 17:10:01, on 13/10/2005
Platform: Windows XP SP2 (WinNT 5.01.2600)
MSIE: Internet Explorer v6.00 SP2 (6.00.2900.2180)

Running processes:
C:\WINDOWS\System32\smss.exe
C:\WINDOWS\system32\csrss.exe
C:\WINDOWS\SYSTEM32\winlogon.exe
C:\WINDOWS\system32\services.exe
C:\WINDOWS\system32\savedump.exe
C:\WINDOWS\system32\lsass.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\system32\svchost.exe
C:\Program Files\Common Files\Symantec Shared\ccSetMgr.exe
C:\Program Files\Common Files\Symantec Shared\SNDSrvc.exe
C:\WINDOWS\Explorer.EXE
C:\Program Files\Common Files\Symantec Shared\SPBBC\SPBBCSvc.exe
C:\Program Files\Common Files\Symantec Shared\ccEvtMgr.exe
C:\WINDOWS\system32\spoolsv.exe
C:\Program Files\Norton AntiVirus\navapsvc.exe
C:\Program Files\Norton AntiVirus\IWP\NPFMntor.exe
C:\WINDOWS\system32\nvsvc32.exe
C:\WINDOWS\system32\svchost.exe
C:\Program Files\Common Files\Symantec Shared\CCPD-LC\symlcsvc.exe
C:\WINDOWS\system32\wdfmgr.exe
C:\WINDOWS\system32\LVCOMSX.EXE
C:\Program Files\Logitech\Video\LogiTray.exe
C:\WINDOWS\system32\RUNDLL32.EXE
C:\Program Files\Common Files\Symantec Shared\ccApp.exe
C:\WINDOWS\system32\qttask.exe
C:\Program Files\CyberLink\PowerDVD\PDVDServ.exe
C:\WINDOWS\system32\ctfmon.exe
C:\Program Files\Washer\washer.exe
C:\Program Files\a2\a2guard.exe
C:\Program Files\SAGEM\SAGEM F@st 800-840\dslmon.exe
C:\Program Files\Logitech\Video\FxSvr2.exe
C:\WINDOWS\System32\alg.exe
C:\Program Files\Common Files\Symantec Shared\NMain.exe
C:\PROGRA~1\NORTON~1\navw32.exe
C:\WINDOWS\system32\wuauclt.exe
C:\Program Files\HijackThis\HijackThis.exe
C:\Program Files\Messenger\msmsgs.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Bar = http://red.clientapps.yahoo.com/customize/ycomp_wave/defaults/sb/*http://www.yahoo.com/search/ie.html
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Page = http://red.clientapps.yahoo.com/customize/ycomp_wave/defaults/sp/*http://www.yahoo.com
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://www.yahoo.co.uk/
R1 - HKCU\Software\Microsoft\Internet Explorer\SearchURL,(Default) = http://red.clientapps.yahoo.com/customize/ycomp_wave/defaults/su/*http://www.yahoo.com
O2 - BHO: AcroIEHlprObj Class - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Adobe\Acrobat 5.0\Reader\ActiveX\AcroIEHelper.ocx
O2 - BHO: (no name) - {53707962-6F74-2D53-2644-206D7942484F} - C:\PROGRA~1\SPYBOT~1\SDHelper.dll
O2 - BHO: CNavExtBho Class - {BDF3E430-B101-42AD-A544-FADC6B084872} - C:\Program Files\Norton AntiVirus\NavShExt.dll
O2 - BHO: FlashFXP Helper for Internet Explorer - {E5A1691B-D188-4419-AD02-90002030B8EE} - C:\PROGRA~1\FlashFXP\IEFlash.dll
O3 - Toolbar: Norton AntiVirus - {42CDD1BF-3FFB-4238-8AD1-7859DF00B1D6} - C:\Program Files\Norton AntiVirus\NavShExt.dll
O4 - HKLM\..\Run: [NvCplDaemon] RUNDLL32.EXE C:\WINDOWS\system32\NvCpl.dll,NvStartup
O4 - HKLM\..\Run: [nwiz] nwiz.exe /install
O4 - HKLM\..\Run: [adiras] adiras.exe
O4 - HKLM\..\Run: [LVCOMSX] C:\WINDOWS\system32\LVCOMSX.EXE
O4 - HKLM\..\Run: [LogitechVideoRepair] C:\Program Files\Logitech\Video\ISStart.exe
O4 - HKLM\..\Run: [LogitechVideoTray] C:\Program Files\Logitech\Video\LogiTray.exe
O4 - HKLM\..\Run: [NvMediaCenter] RUNDLL32.EXE C:\WINDOWS\system32\NvMcTray.dll,NvTaskbarInit
O4 - HKLM\..\Run: [nForce Tray Options] sstray.exe /r
O4 - HKLM\..\Run: [ccApp] "C:\Program Files\Common Files\Symantec Shared\ccApp.exe"
O4 - HKLM\..\Run: [Symantec NetDriver Monitor] C:\PROGRA~1\SYMNET~1\SNDMon.exe /Consumer
O4 - HKLM\..\Run: [NeroFilterCheck] C:\WINDOWS\system32\NeroCheck.exe
O4 - HKLM\..\Run: [QuickTime Task] "C:\WINDOWS\system32\qttask.exe" -atboottime
O4 - HKLM\..\Run: [RemoteControl] "C:\Program Files\CyberLink\PowerDVD\PDVDServ.exe"
O4 - HKCU\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\ctfmon.exe
O4 - HKCU\..\Run: [LogitechSoftwareUpdate] "C:\Program Files\Logitech\Video\ManifestEngine.exe" boot
O4 - HKCU\..\Run: [Washer] C:\Program Files\Washer\washer.exe /0
O4 - HKCU\..\Run: [a-squared] "C:\Program Files\a2\a2guard.exe"
O4 - HKCU\..\RunServicesOnce: [washindex] C:\Program Files\Washer\washidx.exe
O4 - Global Startup: DSLMON.lnk = C:\Program Files\SAGEM\SAGEM F@st 800-840\dslmon.exe
O4 - Global Startup: Spy Sweeper Fix.lnk = C:\Program Files\Webroot\Spy Sweeper\SpySweeperFix.bat
O8 - Extra context menu item: E&xport to Microsoft Excel - res://C:\PROGRA~1\MICROS~2\OFFICE11\EXCEL.EXE/3000
O9 - Extra button: Research - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - C:\PROGRA~1\MICROS~2\OFFICE11\REFIEBAR.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
O16 - DPF: {CE28D5D2-60CF-4C7D-9FE8-0F47A3308078} (ActiveDataInfo Class) - https://www-secure.symantec.com/techsupp/asa/SymAData.cab
O17 - HKLM\System\CCS\Services\Tcpip\..\{7A14A893-FC91-4D96-B248-F36A6A2547C7}: NameServer = 212.74.114.129 212.74.114.193
O23 - Service: Symantec Event Manager (ccEvtMgr) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\ccEvtMgr.exe
O23 - Service: Symantec Password Validation (ccPwdSvc) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\ccPwdSvc.exe
O23 - Service: Symantec Settings Manager (ccSetMgr) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\ccSetMgr.exe
O23 - Service: Service Norton AntiVirus Auto-Protect (navapsvc) - Symantec Corporation - C:\Program Files\Norton AntiVirus\navapsvc.exe
O23 - Service: Norton AntiVirus Firewall Monitor Service (NPFMntor) - Symantec Corporation - C:\Program Files\Norton AntiVirus\IWP\NPFMntor.exe
O23 - Service: NTLOAD - Unknown owner - C:\WINDOWS\SYSTEM\DRIVER\ntsrv.exe
O23 - Service: NVIDIA Display Driver Service (NVSvc) - NVIDIA Corporation - C:\WINDOWS\system32\nvsvc32.exe
O23 - Service: Pml Driver HPZ12 - HP - C:\WINDOWS\system32\HPZipm12.exe
O23 - Service: SAVScan - Symantec Corporation - C:\Program Files\Norton AntiVirus\SAVScan.exe
O23 - Service: ScriptBlocking Service (SBService) - Symantec Corporation - C:\PROGRA~1\COMMON~1\SYMANT~1\SCRIPT~1\SBServ.exe
O23 - Service: Symantec Network Drivers Service (SNDSrvc) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\SNDSrvc.exe
O23 - Service: Symantec SPBBCSvc (SPBBCSvc) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\SPBBC\SPBBCSvc.exe
O23 - Service: Symantec Core LC - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\CCPD-LC\symlcsvc.exe