Explorer.exe occupe le CPU

Bonjour,

Dès que je lance un film, ou lance internet, le processus explorer.exe prend toute la RAM ( 512 Mo, ce qui est peu, je vous l'accorde mais suffisant, nan ? ). Ca fait 4 ans que j'ai mon PC et je présume qqes logicels malfaisants... J'ai fait un scan Avira anti-vir et un Hijackthis ...
En grande recherche d'aide...
Voila le rapport Hijackthis

Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 17:23:05, on 07/06/2008
Platform: Windows XP SP1 (WinNT 5.01.2600)
MSIE: Internet Explorer v6.00 SP1 (6.00.2800.1106)
Boot mode: Normal

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:\WINDOWS\system32\Ati2evxx.exe
C:\WINDOWS\Explorer.EXE
C:\Program Files\QuickTime\qttask.exe
C:\Program Files\Fichiers communs\Real\Update_OB\realsched.exe
C:\Program Files\AntiVir PersonalEdition Classic\avgnt.exe
C:\WINDOWS\System32\ctfmon.exe
C:\Program Files\OpenOffice.org1.1.5\program\OOoVirgTray.exe
C:\Program Files\AntiVir PersonalEdition Classic\sched.exe
C:\Program Files\AntiVir PersonalEdition Classic\avguard.exe
C:\WINDOWS\system32\cisvc.exe
C:\WINDOWS\System32\svchost.exe
C:\Program Files\Mozilla Firefox\firefox.exe
C:\WINDOWS\System32\wuauclt.exe
C:\WINDOWS\System32\wuauclt.exe
C:\Program Files\Trend Micro\HijackThis\HijackThis.exe

R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://www.tele2.fr/redirect/startpage/adsl/fra
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,First Home Page = http://www.tele2.fr/redirect/welcome/adsl/fra
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Window Title = Microsoft Internet Explorer
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Liens
O2 - BHO: AcroIEHlprObj Class - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Adobe\Acrobat 5.0\Reader\ActiveX\AcroIEHelper.ocx
O2 - BHO: (no name) - {7E853D72-626A-48EC-A868-BA8D5E23E045} - (no file)
O2 - BHO: Windows Live Sign-in Helper - {9030D464-4C02-4ABF-8ECC-5164760863C6} - C:\Program Files\Fichiers communs\Microsoft Shared\Windows Live\WindowsLiveLogin.dll
O2 - BHO: ST - {9394EDE7-C8B5-483E-8773-474BF36AF6E4} - C:\Program Files\MSN Apps\ST\01.03.0000.1005\en-xu\stmain.dll
O2 - BHO: MSNToolBandBHO - {BDBD1DAD-C946-4A17-ADC1-64B5B4FF55D0} - C:\Program Files\MSN Apps\MSN Toolbar\01.02.5000.1021\fr\msntb.dll
O3 - Toolbar: &Radio - {8E718888-423F-11D2-876E-00A0C9082467} - C:\WINDOWS\System32\msdxm.ocx
O3 - Toolbar: MSN - {BDAD1DAD-C946-4A17-ADC1-64B5B4FF55D0} - C:\Program Files\MSN Apps\MSN Toolbar\01.02.5000.1021\fr\msntb.dll
O4 - HKLM\..\Run: [NeroFilterCheck] C:\WINDOWS\system32\NeroCheck.exe
O4 - HKLM\..\Run: [QuickTime Task] "C:\Program Files\QuickTime\qttask.exe" -atboottime
O4 - HKLM\..\Run: [TkBellExe] "C:\Program Files\Fichiers communs\Real\Update_OB\realsched.exe" -osboot
O4 - HKLM\..\Run: [avgnt] "C:\Program Files\AntiVir PersonalEdition Classic\avgnt.exe" /min
O4 - HKCU\..\Run: [CTFMON.EXE] C:\WINDOWS\System32\ctfmon.exe
O4 - HKCU\..\Run: [MsnMsgr] "C:\Program Files\MSN Messenger\MsnMsgr.Exe" /background
O4 - HKCU\..\Run: [PathOOOvirg] file:///C:/Program%20Files/OpenOffice.org1.1.5/program/OOoVirgTray.exe
O4 - HKUS\S-1-5-19\..\Run: [CTFMON.EXE] C:\WINDOWS\System32\CTFMON.EXE (User 'SERVICE LOCAL')
O4 - HKUS\S-1-5-20\..\Run: [CTFMON.EXE] C:\WINDOWS\System32\CTFMON.EXE (User 'SERVICE RÉSEAU')
O4 - HKUS\S-1-5-18\..\Run: [CTFMON.EXE] C:\WINDOWS\System32\CTFMON.EXE (User 'SYSTEM')
O4 - HKUS\.DEFAULT\..\Run: [CTFMON.EXE] C:\WINDOWS\System32\CTFMON.EXE (User 'Default user')
O16 - DPF: {56336BCB-3D8A-11D6-A00B-0050DA18DE71} (RdxIE Class) - http://software-dl.real.com/027b379a80230174c915/netzip/RdxIE601_fr.cab
O16 - DPF: {5D6F45B3-9043-443D-A792-115447494D24} (UnoCtrl Class) - http://messenger.zone.msn.com/FR-FR/a-UNO1/GAME_UNO1.cab
O16 - DPF: {6414512B-B978-451D-A0D8-FCFDF33E833C} (WUWebControl Class) - http://v5.windowsupdate.microsoft.com/v5consumer/V5Controls/en/x86/client/wuweb_site.cab?1110035725078
O16 - DPF: {74D05D43-3236-11D4-BDCD-00C04F9A3B61} (HouseCall Control) - https://www.trendmicro.com/en_us/forHome/products/housecall.html
O16 - DPF: {8E0D4DE5-3180-4024-A327-4DFAD1796A8D} (MessengerStatsClient Class) - http://messenger.zone.msn.com/binary/MessengerStatsClient.cab31267.cab
O16 - DPF: {B38870E4-7ECB-40DA-8C6A-595F0A5519FF} (MsnMessengerSetupDownloadControl Class) - http://messenger.msn.com/download/msnmessengersetupdownloader.cab
O16 - DPF: {C3F79A2B-B9B4-4A66-B012-3EE46475B072} (MessengerStatsClient Class) - http://messenger.zone.msn.com/binary/MessengerStatsPAClient.cab56907.cab
O16 - DPF: {F5A7706B-B9C0-4C89-A715-7A0C6B05DD48} (Minesweeper Flags Class) - http://messenger.zone.msn.com/binary/MineSweeper.cab56986.cab
O23 - Service: AntiVir PersonalEdition Classic Scheduler (AntiVirScheduler) - Avira GmbH - C:\Program Files\AntiVir PersonalEdition Classic\sched.exe
O23 - Service: AntiVir PersonalEdition Classic Guard (AntiVirService) - Avira GmbH - C:\Program Files\AntiVir PersonalEdition Classic\avguard.exe
O23 - Service: Ati HotKey Poller - Unknown owner - C:\WINDOWS\System32\Ati2evxx.exe
O23 - Service: Google Updater Service (gusvc) - Google - C:\Program Files\Google\Common\Google Updater\GoogleUpdaterService.exe