PC au ralenti - analyse Hijack This

Mon PC tourne au ralenti, le processeur est très souvent à 100%.
J'ai pas une config terrible, mais il y a qq temps, mon PC tournait bcp mieux.

Athlon XP1800+ avec 512Mo et XP-sp2

Pourriez vous me filer un coup de main dans l'analyse du logfile de HijackThis ?

Merci d'avance,

Vinz

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Logfile of HijackThis v1.99.1
Scan saved at 01:20:37, on 05/10/2006
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\winlogon.exe
C:\WINDOWS\system32\services.exe
C:\WINDOWS\system32\lsass.exe
C:\WINDOWS\system32\Ati2evxx.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\system32\spoolsv.exe
C:\Program Files\AntiVir PersonalEdition Classic\sched.exe
C:\Program Files\AntiVir PersonalEdition Classic\avguard.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\system32\ZoneLabs\vsmon.exe
C:\WINDOWS\system32\Ati2evxx.exe
C:\WINDOWS\Explorer.EXE
C:\Program Files\AntiVir PersonalEdition Classic\avgnt.exe
C:\PROGRAM FILES\ATI TECHNOLOGIES\ATI CONTROL PANEL\ATIPTAXX.EXE
C:\Program Files\Zone Labs\ZoneAlarm\zlclient.exe
C:\Program Files\Spybot - Search & Destroy\TeaTimer.exe
C:\Program Files\Mozilla Firefox\firefox.exe
C:\Documents and Settings\MOI\Bureau\HijackThis.exe

R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Liens
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\jre1.5.0_06\bin\ssv.dll
O2 - BHO: (no name) - {9030D464-4C02-4ABF-8ECC-5164760863C6} - (no file)
O2 - BHO: (no name) - {B0744341-96E0-4341-9ED2-8BC36CE0CCD0} - (no file)
O4 - HKLM\..\Run: [avgnt] "C:\Program Files\AntiVir PersonalEdition Classic\avgnt.exe" /min
O4 - HKLM\..\Run: [ATIPTA] C:\PROGRAM FILES\ATI TECHNOLOGIES\ATI CONTROL PANEL\ATIPTAXX.EXE
O4 - HKLM\..\Run: [Zone Labs Client] "C:\Program Files\Zone Labs\ZoneAlarm\zlclient.exe"
O4 - HKCU\..\Run: [SpybotSD TeaTimer] C:\Program Files\Spybot - Search & Destroy\TeaTimer.exe
O4 - HKCU\..\Run: [Skype] "C:\Program Files\Skype\Phone\Skype.exe" /nosplash /minimized
O6 - HKCU\Software\Policies\Microsoft\Internet Explorer\Control Panel present
O8 - Extra context menu item: E&xporter vers Microsoft Excel - res://C:\PROGRA~1\MICROS~2\OFFICE11\EXCEL.EXE/3000
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.5.0_06\bin\ssv.dll
O9 - Extra 'Tools' menuitem: Console Java (Sun) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.5.0_06\bin\ssv.dll
O9 - Extra button: Recherche - {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
O23 - Service: Adobe LM Service - Adobe Systems - C:\Program Files\Fichiers communs\Adobe Systems Shared\Service\Adobelmsvc.exe
O23 - Service: AntiVir Scheduler (AntiVirScheduler) - Avira GmbH - C:\Program Files\AntiVir PersonalEdition Classic\sched.exe
O23 - Service: AntiVir PersonalEdition Classic Service (AntiVirService) - AVIRA GmbH - C:\Program Files\AntiVir PersonalEdition Classic\avguard.exe
O23 - Service: Ati HotKey Poller - ATI Technologies Inc. - C:\WINDOWS\system32\Ati2evxx.exe
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\11\Intel 32\IDriverT.exe
O23 - Service: TrueVector Internet Monitor (vsmon) - Zone Labs, LLC - C:\WINDOWS\system32\ZoneLabs\vsmon.exe