Redémarrage intempestif + log hijackthis

Bonjour à tous,

Mon PC redémarre de manière quasi systématique au démarrage, parfois plusieurs fois de suite. Une fois l'ecueil du démarrage passé, il peut rédemarrer de manière intempestive, de temps en temps. J'ai du mal à dégager une tendance...
Parfois Internet tourne, parfois pas. Vraiment je ne sais pas...

Je soupçonne un virus.

Voici un log hijackthis de ce matin, après 2 redémarrages:

Logfile of HijackThis v1.99.1
Scan saved at 10:25:56, on 21/03/2008
Platform: Windows XP SP2 (WinNT 5.01.2600)
MSIE: Internet Explorer v7.00 (7.00.5730.0013)

Running processes:
G:\WINDOWS\System32\smss.exe
G:\WINDOWS\system32\winlogon.exe
G:\WINDOWS\system32\services.exe
G:\WINDOWS\system32\lsass.exe
G:\WINDOWS\System32\Ati2evxx.exe
G:\WINDOWS\system32\svchost.exe
G:\WINDOWS\System32\svchost.exe
G:\WINDOWS\Explorer.EXE
G:\Program Files\Alwil Software\Avast4\aswUpdSv.exe
G:\Program Files\Alwil Software\Avast4\ashServ.exe
G:\WINDOWS\system32\spoolsv.exe
G:\Program Files\ATI Technologies\ATI Control Panel\atiptaxx.exe
G:\WINDOWS\SOUNDMAN.EXE
G:\Program Files\HP\HP Software Update\HPWuSchd2.exe
G:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
G:\WINDOWS\system32\ctfmon.exe
G:\Program Files\Microsoft Office\Office\OSA.EXE
G:\Program Files\HP\Digital Imaging\bin\hpqtra08.exe
G:\Program Files\InterVideo\Common\Bin\WinCinemaMgr.exe
G:\Program Files\Microsoft Office\Office\FINDFAST.EXE
G:\Program Files\Sunbelt Software\Personal Firewall\kpf4ss.exe
G:\Program Files\Internet Explorer\iexplore.exe
G:\WINDOWS\System32\svchost.exe
G:\Program Files\Sunbelt Software\Personal Firewall\kpf4gui.exe
G:\Program Files\Alwil Software\Avast4\ashMaiSv.exe
G:\Program Files\Alwil Software\Avast4\ashWebSv.exe
G:\Program Files\Sunbelt Software\Personal Firewall\kpf4gui.exe
G:\WINDOWS\System32\svchost.exe
G:\Program Files\BitTornado\btdownloadgui.exe
H:\Installs\HijackThis.exe

R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = https://fr.yahoo.com/
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://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 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Liens
O2 - BHO: Adobe PDF Reader Link Helper - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - G:\Program Files\Adobe\Acrobat 7.0\ActiveX\AcroIEHelper.dll
O2 - BHO: (no name) - {7E853D72-626A-48EC-A868-BA8D5E23E045} - (no file)
O2 - BHO: Google Toolbar Helper - {AA58ED58-01DD-4d91-8333-CF10577473F7} - g:\program files\google\googletoolbar4.dll
O2 - BHO: FlashFXP Helper for Internet Explorer - {E5A1691B-D188-4419-AD02-90002030B8EE} - G:\PROGRA~1\FlashFXP\IEFlash.dll
O3 - Toolbar: &Google - {2318C2B1-4965-11d4-9B18-009027A5CD4F} - g:\program files\google\googletoolbar4.dll
O4 - HKLM\..\Run: [ATIPTA] G:\Program Files\ATI Technologies\ATI Control Panel\atiptaxx.exe
O4 - HKLM\..\Run: [SoundMan] SOUNDMAN.EXE
O4 - HKLM\..\Run: [*Security Center] secctr.exe
O4 - HKLM\..\Run: [Norton Antivirus 7.0a] G:\WINDOWS\System32\bkoftgi.exe
O4 - HKLM\..\Run: [QuickTime Task] "G:\Program Files\QuickTime\qttask.exe" -atboottime
O4 - HKLM\..\Run: [HP Software Update] "G:\Program Files\HP\HP Software Update\HPWuSchd2.exe"
O4 - HKLM\..\Run: [KernelFaultCheck] %systemroot%\system32\dumprep 0 -k
O4 - HKLM\..\Run: [avast!] G:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
O4 - HKLM\..\RunServices: [*Security Center] secctr.exe
O4 - HKCU\..\Run: [*Security Center] secctr.exe
O4 - HKCU\..\Run: [ctfmon.exe] G:\WINDOWS\system32\ctfmon.exe
O4 - Global Startup: Adobe Gamma Loader.lnk = G:\Program Files\Fichiers communs\Adobe\Calibration\Adobe Gamma Loader.exe
O4 - Global Startup: Adobe Reader Speed Launch.lnk = G:\Program Files\Adobe\Acrobat 7.0\Reader\reader_sl.exe
O4 - Global Startup: Démarrage d'Office.lnk = G:\Program Files\Microsoft Office\Office\OSA.EXE
O4 - Global Startup: HP Digital Imaging Monitor.lnk = G:\Program Files\HP\Digital Imaging\bin\hpqtra08.exe
O4 - Global Startup: InterVideo WinCinema Manager.lnk = G:\Program Files\InterVideo\Common\Bin\WinCinemaMgr.exe
O4 - Global Startup: Microsoft Recherche accélérée.lnk = G:\Program Files\Microsoft Office\Office\FINDFAST.EXE
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - G:\Program Files\Java\jre1.5.0_02\bin\npjpi150_02.dll
O9 - Extra 'Tools' menuitem: Console Java (Sun) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - G:\Program Files\Java\jre1.5.0_02\bin\npjpi150_02.dll
O9 - Extra button: Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - G:\Program Files\Messenger\msmsgs.exe
O9 - Extra 'Tools' menuitem: Windows Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - G:\Program Files\Messenger\msmsgs.exe
O11 - Options group: [INTERNATIONAL] International*
O14 - IERESET.INF: START_PAGE_URL=https://www.free.fr/freebox/index.html
O16 - DPF: {0EB0E74A-2A76-4AB3-A7FB-9BD8C29F7F75} (CKAVWebScan Object) - https://www.kaspersky.fr/?domain=webscanner.kaspersky.fr
O16 - DPF: {6414512B-B978-451D-A0D8-FCFDF33E833C} (WUWebControl Class) - http://update.microsoft.com/...
O16 - DPF: {67DABFBF-D0AB-41FA-9C46-CC0F21721616} - http://download.divx.com/webplayer/stage6/windows/AutoDLDivXWebPlayerInstaller.cab
O16 - DPF: {B38870E4-7ECB-40DA-8C6A-595F0A5519FF} (MsnMessengerSetupDownloadControl Class) - http://messenger.msn.com/download/msnmessengersetupdownloader.cab
O18 - Protocol: livecall - {828030A1-22C1-4009-854F-8E305202313F} - G:\PROGRA~1\MSNMES~1\MSGRAP~1.DLL
O18 - Protocol: msnim - {828030A1-22C1-4009-854F-8E305202313F} - G:\PROGRA~1\MSNMES~1\MSGRAP~1.DLL
O20 - Winlogon Notify: WgaLogon - G:\WINDOWS\
O23 - Service: avast! iAVS4 Control Service (aswUpdSv) - ALWIL Software - G:\Program Files\Alwil Software\Avast4\aswUpdSv.exe
O23 - Service: Ati HotKey Poller - Unknown owner - G:\WINDOWS\System32\Ati2evxx.exe
O23 - Service: ATI Smart - Unknown owner - G:\WINDOWS\system32\ati2sgag.exe
O23 - Service: avast! Antivirus - ALWIL Software - G:\Program Files\Alwil Software\Avast4\ashServ.exe
O23 - Service: avast! Mail Scanner - Unknown owner - G:\Program Files\Alwil Software\Avast4\ashMaiSv.exe" /service (file missing)
O23 - Service: avast! Web Scanner - Unknown owner - G:\Program Files\Alwil Software\Avast4\ashWebSv.exe" /service (file missing)
O23 - Service: Hardware Clock Driver (hwclock) - Unknown owner - G:\WINDOWS\System32\hwclock.exe (file missing)
O23 - Service: InstallDriver Table Manager (IDriverT) - Macrovision Corporation - G:\Program Files\Fichiers communs\InstallShield\Driver\11\Intel 32\IDriverT.exe
O23 - Service: Keyboard Service System Files (Keyboard Service) - Unknown owner - G:\WINDOWS\system32\winDLL32.exe (file missing)
O23 - Service: Macromedia Licensing Service - Macromedia - G:\Program Files\Fichiers communs\Macromedia Shared\Service\Macromedia Licensing.exe
O23 - Service: Pml Driver HPZ12 - HP - G:\WINDOWS\system32\HPZipm12.exe
O23 - Service: Smart Card Client (SCardClnt) - Unknown owner - G:\WINDOWS\System32\SCardClnt.exe (file missing)
O23 - Service: Sunbelt Personal Firewall 4 (SPF4) - Sunbelt Software - G:\Program Files\Sunbelt Software\Personal Firewall\kpf4ss.exe


Merci,
MaGa