Ralentissement PC

Bonjour,

Depuis 1 mois environ, j'ai noté des ralentissements sur mon PC, j'aimerais connaître votre opinion ne sachant que faire, je joins le dernier log Hijack :

Logfile of HijackThis v1.99.1
Scan saved at 02:20:36, on 23/09/2009
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\Ati2evxx.exe
C:\Program Files\Lavasoft\Ad-Aware\aawservice.exe
C:\Program Files\Alwil Software\Avast4\aswUpdSv.exe
C:\Program Files\Alwil Software\Avast4\ashServ.exe
C:\WINDOWS\Explorer.EXE
C:\WINDOWS\RTHDCPL.EXE
C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
C:\Program Files\ScanSoft\OmniPagePro12.0\Opware12.exe
C:\Program Files\HP\HP Software Update\HPWuSchd2.exe
C:\Program Files\Avira\AntiVir Desktop\avgnt.exe
C:\Program Files\Java\jre6\bin\jusched.exe
C:\Program Files\Google\GoogleToolbarNotifier\GoogleToolbarNotifier.exe
C:\Program Files\ATI Technologies\ATI.ACE\Core-Static\MOM.exe
C:\Program Files\Windows Live\Messenger\MsnMsgr.Exe
C:\WINDOWS\system32\spoolsv.exe
C:\Program Files\Avira\AntiVir Desktop\sched.exe
C:\Program Files\Olympus\DeviceDetector\DevDtct2.exe
C:\Program Files\HP\Digital Imaging\bin\hpqtra08.exe
C:\Program Files\Avira\AntiVir Desktop\avguard.exe
C:\WINDOWS\ATKKBService.exe
C:\Program Files\Olympus\DeviceDetector\DM1Service.exe
C:\Program Files\HP\Digital Imaging\bin\hpqgalry.exe
C:\Program Files\Java\jre6\bin\jqs.exe
C:\Program Files\Nero\Nero8\Nero BackItUp\NBService.exe
C:\Program Files\ATI Technologies\ATI.ACE\Core-Static\ccc.exe
C:\WINDOWS\system32\HPZipm12.exe
C:\WINDOWS\system32\svchost.exe
C:\Program Files\Alwil Software\Avast4\ashMaiSv.exe
C:\Program Files\Alwil Software\Avast4\ashWebSv.exe
C:\Program Files\Spybot - Search & Destroy\TeaTimer.exe
C:\Documents and Settings\Admin\Bureau\Sécurité\Hijack\HijackThis-fr-Colok.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Bar = http://www.google.fr/toolbar/ie8/sidebar.html
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Page = https://www.google.fr/?gws_rd=ssl
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = https://www.msn.com/fr-fr/?ocid=iehp
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,SearchAssistant = http://www.google.fr/toolbar/ie8/sidebar.html
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Window Title = Alice ADSL
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Liens
O2 - BHO: AcroIEHelperStub - {18DF081C-E8AD-4283-A596-FA578C2EBDC3} - C:\Program Files\Fichiers communs\Adobe\Acrobat\ActiveX\AcroIEHelperShim.dll
O2 - BHO: Spybot-S&D IE Protection - {53707962-6F74-2D53-2644-206D7942484F} - C:\Program Files\Spybot - Search & Destroy\SDHelper.dll
O2 - BHO: -Sans nom - {5C255C8A-E604-49b4-9D64-90988571CECB} - -Manquant
O2 - BHO: Programme d'aide de l'Assistant de connexion Windows Live - {9030D464-4C02-4ABF-8ECC-5164760863C6} - C:\Program Files\Fichiers communs\Microsoft Shared\Windows Live\WindowsLiveLogin.dll
O2 - BHO: Google Toolbar Helper - {AA58ED58-01DD-4d91-8333-CF10577473F7} - C:\Program Files\Google\Google Toolbar\GoogleToolbar_32.dll
O2 - BHO: Google Toolbar Notifier BHO - {AF69DE43-7D58-4638-B6FA-CE66B5AD205D} - C:\Program Files\Google\GoogleToolbarNotifier\5.2.4204.1700\swg.dll
O2 - BHO: Google Dictionary Compression sdch - {C84D72FE-E17D-4195-BB24-76C02E2E7C4E} - C:\Program Files\Google\Google Toolbar\Component\fastsearch_B7C5AC242193BB3E.dll
O2 - BHO: Java(tm) Plug-In 2 SSV Helper - {DBC80044-A445-435b-BC74-9C25C1C588A9} - C:\Program Files\Java\jre6\bin\jp2ssv.dll
O3 -BarreOut. Google Toolbar - {2318C2B1-4965-11d4-9B18-009027A5CD4F} - C:\Program Files\Google\Google Toolbar\GoogleToolbar_32.dll
O4 - HKLM\..\Run: [RTHDCPL] RTHDCPL.EXE
O4 - HKLM\..\Run: [Alcmtr] ALCMTR.EXE
O4 - HKLM\..\Run: [NBKeyScan] "C:\Program Files\Nero\Nero8\Nero BackItUp\NBKeyScan.exe"
O4 - HKLM\..\Run: [avast!] C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
O4 - HKLM\..\Run: [QuickTime Task] "C:\Program Files\QuickTime\qttask.exe" -atboottime
O4 - HKLM\..\Run: [Opware12] "C:\Program Files\ScanSoft\OmniPagePro12.0\Opware12.exe"
O4 - HKLM\..\Run: [KernelFaultCheck] %systemroot%\system32\dumprep 0 -k
O4 - HKLM\..\Run: [HP Software Update] C:\Program Files\HP\HP Software Update\HPWuSchd2.exe
O4 - HKLM\..\Run: [StartCCC] "C:\Program Files\ATI Technologies\ATI.ACE\Core-Static\CLIStart.exe" MSRun
O4 - HKLM\..\Run: [avgnt] "C:\Program Files\Avira\AntiVir Desktop\avgnt.exe" /min
O4 - HKLM\..\Run: [Adobe Reader Speed Launcher] "C:\Program Files\Adobe\Reader 9.0\Reader\Reader_sl.exe"
O4 - HKLM\..\Run: [SunJavaUpdateSched] "C:\Program Files\Java\jre6\bin\jusched.exe"
O4 - HKCU\..\Run: [swg] "C:\Program Files\Google\GoogleToolbarNotifier\GoogleToolbarNotifier.exe"
O4 - HKCU\..\Run: [SpybotSD TeaTimer] C:\Program Files\Spybot - Search & Destroy\TeaTimer.exe
O4 - HKCU\..\Run: [MsnMsgr] "C:\Program Files\Windows Live\Messenger\MsnMsgr.Exe" /background
O4 - Startup: IMVU.lnk = C:\Program Files\IMVU\IMVUClient.exe
O4 - Global Startup: Device Detector 3.lnk = C:\Program Files\Olympus\DeviceDetector\DevDtct2.exe
O4 - Global Startup: Démarrage rapide du logiciel HP Image Zone.lnk = C:\Program Files\HP\Digital Imaging\bin\hpqthb08.exe
O4 - Global Startup: HP Digital Imaging Monitor.lnk = C:\Program Files\HP\Digital Imaging\bin\hpqtra08.exe
O8 - Extra du menu contextuel E&xporter vers Microsoft Excel - res://C:\PROGRA~1\MICROS~2\OFFICE11\EXCEL.EXE/3000
O9 - Bouton Extra: Recherche - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - C:\PROGRA~1\MICROS~2\OFFICE11\REFIEBAR.DLL
O9 - Bouton Extra: Run IMVU - {d9288080-1baa-4bc4-9cf8-a92d743db949} - C:\Documents and Settings\Admin\Menu Démarrer\Programmes\IMVU\Run IMVU.lnk
O9 - Bouton Extra: -Sans nom - {DFB852A3-47F8-48C4-A200-58CAB36FD2A2} - C:\Program Files\Spybot - Search & Destroy\SDHelper.dll
O9 - Outil Extra du menu : Spybot - Search && Destroy Configuration - {DFB852A3-47F8-48C4-A200-58CAB36FD2A2} - C:\Program Files\Spybot - Search & Destroy\SDHelper.dll
O15 - Trusted Zone: http://www.secuser.com
O16 - DPF: {CF40ACC5-E1BB-4AFF-AC72-04C2F616BCA7} -
O16 - DPF: {E2883E8F-472F-4FB0-9522-AC9BF37916A7} - http://platformdl.adobe.com/NOS/getPlusPlus/1.6/gp.cab
O18 - Protocol: livecall - {828030A1-22C1-4009-854F-8E305202313F} - C:\PROGRA~1\WINDOW~4\MESSEN~1\MSGRAP~1.DLL
O18 - Protocol: msnim - {828030A1-22C1-4009-854F-8E305202313F} - C:\PROGRA~1\WINDOW~4\MESSEN~1\MSGRAP~1.DLL
O23 - Service: Lavasoft Ad-Aware Service (aawservice) - Lavasoft - C:\Program Files\Lavasoft\Ad-Aware\aawservice.exe
O23 - Service: Avira AntiVir Planificateur (AntiVirSchedulerService) - Avira GmbH - C:\Program Files\Avira\AntiVir Desktop\sched.exe
O23 - Service: Avira AntiVir Guard (AntiVirService) - Avira GmbH - C:\Program Files\Avira\AntiVir Desktop\avguard.exe
O23 - Service: avast! iAVS4 Control Service (aswUpdSv) - ALWIL Software - C:\Program Files\Alwil Software\Avast4\aswUpdSv.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: ATK Keyboard Service (ATKKeyboardService) - ASUSTeK COMPUTER INC. - C:\WINDOWS\ATKKBService.exe
O23 - Service: avast! Antivirus - ALWIL Software - C:\Program Files\Alwil Software\Avast4\ashServ.exe
O23 - Service: avast! Mail Scanner - Unknown owner - C:\Program Files\Alwil Software\Avast4\ashMaiSv.exe" /service (file missing)
O23 - Service: avast! Web Scanner - Unknown owner - C:\Program Files\Alwil Software\Avast4\ashWebSv.exe" /service (file missing)
O23 - Service: DM1Service - OLYMPUS Corporation - C:\Program Files\Olympus\DeviceDetector\DM1Service.exe
O23 - Service: Google Software Updater (gusvc) - Google - C:\Program Files\Google\Common\Google Updater\GoogleUpdaterService.exe
O23 - Service: Java Quick Starter (JavaQuickStarterService) - Unknown owner - C:\Program Files\Java\jre6\bin\jqs.exe" -service -config "C:\Program Files\Java\jre6\lib\deploy\jqs\jqs.conf (file missing)
O23 - Service: Nero BackItUp Scheduler 3 - Nero AG - C:\Program Files\Nero\Nero8\Nero BackItUp\NBService.exe
O23 - Service: NMIndexingService - Nero AG - C:\Program Files\Fichiers communs\Nero\Lib\NMIndexingService.exe
O23 - Service: Pml Driver HPZ12 - HP - C:\WINDOWS\system32\HPZipm12.exe

Merci d'avance pour vos réponses ^^