Ralentissement PC (principalement internet)

Bonjour,
Depuis quelques mois (depuis le nouveau Firefox 3 je dirais, mais apparement ca n'a aucun rapport ^^), Internet rame considérablement, que ce soit pour ouvrir une page, des freezes toutes les 30sec, ou même des crashs sans aucune raison. Jusque la, le problème ne m'avait pas spécialement déranger, mais depuis quelques jours c'est vraiment insupportable, et le reste du PC suit, ouvrir un dossier ou une appli devient un vrai travail de patience.
Je suis sous Vista, ma config est pas géniallissime mais n'a jamais posé de problème.

Voila un rapport de HijackThis, apparement c'est la coutume pour ce genre de problème :

Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 19:02:23, on 18/10/2008
Platform: Windows Vista SP1 (WinNT 6.00.1905)
MSIE: Internet Explorer v7.00 (7.00.6001.18000)
Boot mode: Normal

Running processes:
C:\Windows\system32\taskeng.exe
C:\Windows\system32\Dwm.exe
C:\Windows\Explorer.EXE
C:\Windows\RtHDVCpl.exe
C:\Program Files\Google\Google Desktop Search\GoogleDesktop.exe
C:\Program Files\Synaptics\SynTP\SynTPEnh.exe
C:\Program Files\Common Files\aol\1172488718\ee\aolsoftware.exe
C:\Program Files\iTunes\iTunesHelper.exe
C:\Program Files\Windows Live\Messenger\msnmsgr.exe
C:\Program Files\RescueTime\RescueTime.exe
C:\Program Files\Common Files\Symantec Shared\ccSvcHst.exe
C:\Windows\ehome\ehtray.exe
C:\Windows\ehome\ehmsas.exe
C:\Program Files\Windows Media Player\wmpnscfg.exe
C:\Program Files\ATI Technologies\ATI.ACE\CLI.EXE
C:\Program Files\Google\Google Desktop Search\GoogleDesktop.exe
C:\Program Files\ATI Technologies\ATI.ACE\CLI.exe
C:\Program Files\ATI Technologies\ATI.ACE\CLI.exe
C:\Program Files\Megaupload\Mega Manager\MegaManager.exe
C:\Windows\system32\conime.exe
C:\Program Files\Mozilla Firefox\firefox.exe
C:\Program Files\Windows Media Player\wmplayer.exe
C:\Windows\explorer.exe
C:\Program Files\Trend Micro\HijackThis\HijackThis.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Page = https://www.bing.com/?toHttps=1&redig=5FC791212101479BAFBE1A679848B1AF
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = https://www.deezer.com/fr/
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 - HKLM\Software\Microsoft\Internet Explorer\Search,SearchAssistant =
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,CustomizeSearch =
R1 - HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings,ProxyOverride = *.local
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName =
R3 - URLSearchHook: Yahoo! Toolbar avec bloqueur de fenêtres pop-up - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - C:\Program Files\Yahoo!\Companion\Installs\cpn\yt.dll
O1 - Hosts: ::1 localhost
O2 - BHO: Yahoo! Toolbar Helper - {02478D38-C3F9-4EFB-9B51-7695ECA05670} - C:\Program Files\Yahoo!\Companion\Installs\cpn\yt.dll
O2 - BHO: Aide pour le lien d'Adobe PDF Reader - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Common Files\Adobe\Acrobat\ActiveX\AcroIEHelper.dll
O2 - BHO: Megaupload Toolbar - {4E7BD74F-2B8D-469E-CCB0-B130EEDBE97C} - C:\PROGRA~1\MEGAUP~2\MEGAUP~1.DLL
O2 - BHO: NCO 2.0 IE BHO - {602ADB0E-4AFF-4217-8AA1-95DAC4DFA408} - C:\Program Files\Common Files\Symantec Shared\coShared\Browser\2.6\coIEPlg.dll
O2 - BHO: Symantec Intrusion Prevention - {6D53EC84-6AAE-4787-AEEE-F4628F01010C} - C:\PROGRA~1\COMMON~1\SYMANT~1\IDS\IPSBHO.dll
O2 - BHO: (no name) - {7E853D72-626A-48EC-A868-BA8D5E23E045} - (no file)
O2 - BHO: Programme d'aide de l'Assistant de connexion Windows Live - {9030D464-4C02-4ABF-8ECC-5164760863C6} - C:\Program Files\Common Files\Microsoft Shared\Windows Live\WindowsLiveLogin.dll
O2 - BHO: MegaIEMn - {bf00e119-21a3-4fd1-b178-3b8537e75c92} - C:\Program Files\Megaupload\Mega Manager\MegaIEMn.dll
O2 - BHO: CBrowserHelperObject Object - {CA6319C0-31B7-401E-A518-A07C3DB8F777} - C:\Program Files\Google\Google_BAE\BAE.dll
O3 - Toolbar: Yahoo! Toolbar avec bloqueur de fenêtres pop-up - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - C:\Program Files\Yahoo!\Companion\Installs\cpn\yt.dll
O3 - Toolbar: Megaupload Toolbar - {4E7BD74F-2B8D-469E-CCB0-B130EEDBE97C} - C:\PROGRA~1\MEGAUP~2\MEGAUP~1.DLL
O3 - Toolbar: Show Norton Toolbar - {7FEBEFE3-6B19-4349-98D2-FFB09D4B49CA} - C:\Program Files\Common Files\Symantec Shared\coShared\Browser\2.6\CoIEPlg.dll
O4 - HKLM\..\Run: [Windows Defender] %ProgramFiles%\Windows Defender\MSASCui.exe -hide
O4 - HKLM\..\Run: [RtHDVCpl] RtHDVCpl.exe
O4 - HKLM\..\Run: [Google Desktop Search] "C:\Program Files\Google\Google Desktop Search\GoogleDesktop.exe" /startup
O4 - HKLM\..\Run: [toolbar_eula_launcher] C:\Program Files\Packard Bell\GOOGLE_EULA\EULALauncher.exe
O4 - HKLM\..\Run: [ccApp] "C:\Program Files\Common Files\Symantec Shared\ccApp.exe"
O4 - HKLM\..\Run: [osCheck] "C:\Program Files\Norton 360\osCheck.exe"
O4 - HKLM\..\Run: [SynTPEnh] C:\Program Files\Synaptics\SynTP\SynTPEnh.exe
O4 - HKLM\..\Run: [HostManager] C:\Program Files\Common Files\AOL\1172488718\ee\AOLSoftware.exe
O4 - HKLM\..\Run: [ATICCC] "C:\Program Files\ATI Technologies\ATI.ACE\CLIStart.exe"
O4 - HKLM\..\Run: [Adobe Reader Speed Launcher] "C:\Program Files\Adobe\Reader 8.0\Reader\Reader_sl.exe"
O4 - HKLM\..\Run: [QuickTime Task] "C:\Program Files\QuickTime\QTTask.exe" -atboottime
O4 - HKLM\..\Run: [AppleSyncNotifier] C:\Program Files\Common Files\Apple\Mobile Device Support\bin\AppleSyncNotifier.exe
O4 - HKLM\..\Run: [iTunesHelper] "C:\Program Files\iTunes\iTunesHelper.exe"
O4 - HKCU\..\Run: [ehTray.exe] C:\Windows\ehome\ehTray.exe
O4 - HKCU\..\Run: [msnmsgr] "C:\Program Files\Windows Live\Messenger\msnmsgr.exe" /background
O4 - HKCU\..\Run: [Mega Manager] C:\Program Files\Megaupload\
O4 - HKCU\..\Run: [WMPNSCFG] C:\Program Files\Windows Media Player\WMPNSCFG.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')
O4 - Startup: RescueTime.lnk = C:\Program Files\RescueTime\RescueTime.exe
O8 - Extra context menu item: E&xporter vers Microsoft Excel - res://C:\PROGRA~1\MICROS~2\OFFICE11\EXCEL.EXE/3000
O8 - Extra context menu item: Liens de téléchargement avec Mega Manager... - C:\Program Files\Megaupload\Mega Manager\mm_file.htm
O9 - Extra button: Recherche - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - C:\PROGRA~1\MICROS~2\OFFICE11\REFIEBAR.DLL
O13 - Gopher Prefix:
O20 - AppInit_DLLs: C:\PROGRA~1\Google\GOOGLE~2\GOEC62~1.DLL
O23 - Service: AOL Connectivity Service (AOL ACS) - AOL LLC - C:\Program Files\Common Files\AOL\ACS\AOLAcsd.exe
O23 - Service: Apple Mobile Device - Apple Inc. - C:\Program Files\Common Files\Apple\Mobile Device Support\bin\AppleMobileDeviceService.exe
O23 - Service: Ati External Event Utility - ATI Technologies Inc. - C:\Windows\system32\Ati2evxx.exe
O23 - Service: Planificateur LiveUpdate automatique (Automatic LiveUpdate Scheduler) - Symantec Corporation - C:\Program Files\Symantec\LiveUpdate\AluSchedulerSvc.exe
O23 - Service: Service Bonjour (Bonjour Service) - Apple Inc. - C:\Program Files\Bonjour\mDNSResponder.exe
O23 - Service: Symantec Event Manager (ccEvtMgr) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\ccSvcHst.exe
O23 - Service: Symantec Settings Manager (ccSetMgr) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\ccSvcHst.exe
O23 - Service: Symantec Lic NetConnect service (CLTNetCnService) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\ccSvcHst.exe
O23 - Service: COM Host (comHost) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\VAScanner\comHost.exe
O23 - Service: FreezeScreenSaver - Unknown owner - C:\Windows\system32\FreezeScreenSaver.exe
O23 - Service: Google Desktop Manager 5.7.806.10245 (GoogleDesktopManager-061008-081103) - Google - C:\Program Files\Google\Google Desktop Search\GoogleDesktop.exe
O23 - Service: Service de l’iPod (iPod Service) - Apple Inc. - C:\Program Files\iPod\bin\iPodService.exe
O23 - Service: LiveUpdate - Symantec Corporation - C:\Program Files\Symantec\LiveUpdate\LuComServer_3_4.EXE
O23 - Service: LiveUpdate Notice - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\ccSvcHst.exe
O23 - Service: Symantec Core LC - Unknown owner - C:\PROGRA~1\COMMON~1\SYMANT~1\CCPD-LC\symlcsvc.exe