Pc tres lent, antivirus inneficaces

Bonjour,
je voudrais vous demander de l'aide car depuis quelques jours, mon PC est plus lent qu'un PC datant d'y y a 7 ans.....
En fait, je crois que j'ai des virus, mais ne sais pas où et aucun des mes programmes de protection n'en dénoue (j'en ai pourtant 4: spybot, ad-aware, avira et ZoneAlarm). (je sais que ad-aware et spybot sont plutôt incompatibles, mais je voulais comparer les résultats....
Quoi qu'il en soit, mon PC est très lent dès lors que je l'allume, puis se calme au bout d'un certain temps (peut-être 15 ou 30 minutes) après allumage, mais se met de nouveau en mode pagaie (enfin, il rame quoi....) lorsque je me connecte a internet.
J'ai vu qu'un rapport HiJackThis pouvait aider a déceler la(les) raison(s) donc j'en ai fait un:

Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 16:19:24, on 24-Sep-09
Platform: Windows Vista SP2 (WinNT 6.00.1906)
MSIE: Internet Explorer v8.00 (8.00.6001.18813)
Boot mode: Normal

Running processes:
C:\Windows\system32\taskeng.exe
C:\Windows\Explorer.EXE
C:\Program Files\Synaptics\SynTP\SynTPEnh.exe
C:\Windows\System32\hkcmd.exe
C:\Windows\System32\igfxpers.exe
C:\Windows\system32\igfxsrvc.exe
C:\Windows\RtHDVCpl.exe
C:\Program Files\Launch Manager\LManager.exe
C:\Program Files\Lavasoft\Ad-Aware\AAWTray.exe
C:\Windows\system32\igfxext.exe
C:\Windows\system32\igfxsrvc.exe
C:\Program Files\Avira\AntiVir Desktop\avgnt.exe
C:\Program Files\Java\jre6\bin\jusched.exe
C:\Program Files\Zone Labs\ZoneAlarm\zlclient.exe
C:\Users\MAAXII~1\AppData\Local\Temp\RtkBtMnt.exe
C:\Program Files\Synaptics\SynTP\SynTPHelper.exe
C:\Users\Maaxiimee\AppData\Local\Google\Chrome\Application\chrome.exe
C:\Users\Maaxiimee\AppData\Local\Google\Chrome\Application\chrome.exe
C:\Users\Maaxiimee\AppData\Local\Google\Chrome\Application\chrome.exe
C:\Users\Maaxiimee\Documents\Downloads\HiJackThis.exe
C:\Program Files\Windows Live\Mail\wlmail.exe
C:\Windows\system32\SearchFilterHost.exe
C:\Program Files\Windows Live\Contacts\wlcomm.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://homepage.acer.com/rdr.aspx?b=ACAW&l=040c&s=2&o=vb32&d=0209&m=aspire_5735
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Page = https://www.bing.com/?toHttps=1&redig=5FC791212101479BAFBE1A679848B1AF
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://homepage.acer.com/rdr.aspx?b=ACAW&l=040c&s=2&o=vb32&d=0209&m=aspire_5735
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 = http://homepage.acer.com/rdr.aspx?b=ACAW&l=040c&s=2&o=vb32&d=0209&m=aspire_5735
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 =
O2 - BHO: AcroIEHelperStub - {18DF081C-E8AD-4283-A596-FA578C2EBDC3} - C:\Program Files\Common Files\Adobe\Acrobat\ActiveX\AcroIEHelperShim.dll
O2 - BHO: QQ??? - {29CF293A-1E7D-4069-9E11-E39698D0AF95} - C:\Program Files\Tencent\QQToolbar\IEBar.dll
O2 - BHO: WormRadar.com IESiteBlocker.NavFilter - {3CA2F312-6F6E-4B53-A66E-4E65E497C8C0} - C:\Program Files\AVG\AVG8\avgssie.dll
O2 - BHO: (no name) - {5C255C8A-E604-49b4-9D64-90988571CECB} - (no file)
O2 - BHO: ShowBarObj Class - {83A2F9B1-01A2-4AA5-87D1-45B6B8505E96} - C:\Program Files\Acer\Empowering Technology\eDataSecurity\x86\ActiveToolBand.dll
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: 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\5.3.4501.1418\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 - Toolbar: Acer eDataSecurity Management - {5CBE3B7C-1E47-477e-A7DD-396DB0476E29} - C:\Program Files\Acer\Empowering Technology\eDataSecurity\x86\eDStoolbar.dll
O3 - Toolbar: Google Toolbar - {2318C2B1-4965-11d4-9B18-009027A5CD4F} - C:\Program Files\Google\Google Toolbar\GoogleToolbar_32.dll
O3 - Toolbar: DAEMON Tools Toolbar - {32099AAC-C132-4136-9E9A-4E364A424E17} - C:\Program Files\DAEMON Tools Toolbar\DTToolbar.dll
O3 - Toolbar: QQ??? - {29CF293A-1E7D-4069-9E11-E39698D0AF95} - C:\Program Files\Tencent\QQToolbar\IEBar.dll
O4 - HKLM\..\Run: [Windows Defender] %ProgramFiles%\Windows Defender\MSASCui.exe -hide
O4 - HKLM\..\Run: [SynTPEnh] C:\Program Files\Synaptics\SynTP\SynTPEnh.exe
O4 - HKLM\..\Run: [IgfxTray] C:\Windows\system32\igfxtray.exe
O4 - HKLM\..\Run: [HotKeysCmds] C:\Windows\system32\hkcmd.exe
O4 - HKLM\..\Run: [Persistence] C:\Windows\system32\igfxpers.exe
O4 - HKLM\..\Run: [RtHDVCpl] RtHDVCpl.exe
O4 - HKLM\..\Run: [LManager] C:\PROGRA~1\LAUNCH~1\LManager.exe
O4 - HKLM\..\Run: [eDataSecurity Loader] C:\Program Files\Acer\Empowering Technology\eDataSecurity\x86\eDSloader.exe
O4 - HKLM\..\Run: [ePower_DMC] C:\Program Files\Acer\Empowering Technology\ePower\ePower_DMC.exe
O4 - HKLM\..\Run: [Ad-Watch] C:\Program Files\Lavasoft\Ad-Aware\AAWTray.exe
O4 - HKLM\..\Run: [Adobe Reader Speed Launcher] "C:\Program Files\Adobe\Reader 9.0\Reader\Reader_sl.exe"
O4 - HKLM\..\Run: [QuickTime Task] "C:\Program Files\QuickTime\QTTask.exe" -atboottime
O4 - HKLM\..\Run: [avgnt] "C:\Program Files\Avira\AntiVir Desktop\avgnt.exe" /min
O4 - HKLM\..\Run: [SunJavaUpdateSched] "C:\Program Files\Java\jre6\bin\jusched.exe"
O4 - HKLM\..\Run: [ZoneAlarm Client] "C:\Program Files\Zone Labs\ZoneAlarm\zlclient.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')
O9 - Extra button: Ajout Direct - {219C3416-8CB2-491a-A3C7-D9FCDDC9D600} - C:\Program Files\Windows Live\Writer\WriterBrowserExtension.dll
O9 - Extra 'Tools' menuitem: &Ajout Direct dans Windows Live Writer - {219C3416-8CB2-491a-A3C7-D9FCDDC9D600} - C:\Program Files\Windows Live\Writer\WriterBrowserExtension.dll
O9 - Extra button: Bonjour - {7F9DB11C-E358-4ca6-A83D-ACC663939424} - C:\Program Files\Bonjour\ExplorerPlugin.dll
O13 - Gopher Prefix:
O16 - DPF: {C3F79A2B-B9B4-4A66-B012-3EE46475B072} (MessengerStatsClient Class) - http://messenger.zone.msn.com/binary/MessengerStatsPAClient.cab56907.cab
O16 - DPF: {D27CDB6E-AE6D-11CF-96B8-444553540000} (Shockwave Flash Object) - http://fpdownload2.macromedia.com/get/shockwave/cabs/flash/swflash.cab
O18 - Protocol: linkscanner - {F274614C-63F8-47D5-A4D1-FBDDE494F8D1} - C:\Program Files\AVG\AVG8\avgpp.dll
O18 - Protocol: skype4com - {FFC8B962-9B40-4DFF-9458-1830C7DD7F5D} - C:\PROGRA~1\COMMON~1\Skype\SKYPE4~1.DLL
O23 - Service: Agere Modem Call Progress Audio (AgereModemAudio) - Agere Systems - C:\Windows\system32\agrsmsvc.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: AVG Free8 E-mail Scanner (avg8emc) - AVG Technologies CZ, s.r.o. - C:\PROGRA~1\AVG\AVG8\avgemc.exe
O23 - Service: AVG Free8 WatchDog (avg8wd) - AVG Technologies CZ, s.r.o. - C:\PROGRA~1\AVG\AVG8\avgwdsvc.exe
O23 - Service: Bonjour Service - Apple Inc. - C:\Program Files\Bonjour\mDNSResponder.exe
O23 - Service: NTI Backup Now 5 Agent Service (BUNAgentSvc) - NewTech Infosystems, Inc. - C:\Program Files\NewTech Infosystems\NTI Backup Now 5\Client\Agentsvc.exe
O23 - Service: CLHNService - Unknown owner - C:\Program Files\Acer Arcade Deluxe\HomeMedia\Kernel\DMP\CLHNService.exe
O23 - Service: eDataSecurity Service - Egis Incorporated - C:\Program Files\Acer\Empowering Technology\eDataSecurity\x86\eDSService.exe
O23 - Service: Empowering Technology Service (ETService) - Unknown owner - C:\Program Files\Acer\Empowering Technology\Service\ETService.exe
O23 - Service: Google Software Updater (gusvc) - Google - C:\Program Files\Google\Common\Google Updater\GoogleUpdaterService.exe
O23 - Service: InstallDriver Table Manager (IDriverT) - Macrovision Corporation - C:\Program Files\Common Files\InstallShield\Driver\11\Intel 32\IDriverT.exe
O23 - Service: Lavasoft Ad-Aware Service - Lavasoft - C:\Program Files\Lavasoft\Ad-Aware\AAWService.exe
O23 - Service: LightScribeService Direct Disc Labeling Service (LightScribeService) - Hewlett-Packard Company - C:\Program Files\Common Files\LightScribe\LSSrvc.exe
O23 - Service: MobilityService - Unknown owner - C:\Acer\Mobility Center\MobilityService.exe
O23 - Service: nProtect GameGuard Service (npggsvc) - Unknown owner - C:\Windows\system32\GameMon.des.exe (file missing)
O23 - Service: NTI Backup Now 5 Backup Service (NTIBackupSvc) - NewTech InfoSystems, Inc. - C:\Program Files\NewTech Infosystems\NTI Backup Now 5\BackupSvc.exe
O23 - Service: NTI Backup Now 5 Scheduler Service (NTISchedulerSvc) - Unknown owner - C:\Program Files\NewTech Infosystems\NTI Backup Now 5\SchedulerSvc.exe
O23 - Service: Cyberlink RichVideo Service(CRVS) (RichVideo) - Unknown owner - c:\Program Files\Cyberlink\Shared files\RichVideo.exe
O23 - Service: SBSD Security Center Service (SBSDWSCService) - Safer Networking Ltd. - C:\Program Files\Spybot - Search & Destroy\SDWinSec.exe
O23 - Service: TrueVector Internet Monitor (vsmon) - Check Point Software Technologies LTD - C:\Windows\System32\ZoneLabs\vsmon.exe