Pc extrêment lent

Bonjour,

voila j'ai un portable acer depuis quelques temps et il est devenue de plus en plus lent comme c'est pas possible comme par exemple 5 minutes pour lancer firefox, après que le pc soit bien démarré ( directement en allumant c'est pas la peine il faut un bon quart d'heure...). j'ai fais un peu de nettoyage ( scan avira et spybot, jkdefrag , ccleaner ) mais c'est pas encore ça.

Je poste le rapport de Hijackthis si vous pouviez m'aider :

Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 18:50:29, on 20/05/2011
Platform: Unknown Windows (WinNT 6.01.3504)
MSIE: Internet Explorer v8.00 (8.00.7600.16766)
Boot mode: Normal

Running processes:
C:\Windows\PLFSetI.exe
C:\Program Files (x86)\Spybot - Search & Destroy\TeaTimer.exe
C:\Program Files (x86)\Avira\AntiVir Desktop\avgnt.exe
C:\Program Files (x86)\Trend Micro\HijackThis\HijackThis.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://homepage.acer.com/...
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Page = http://go.microsoft.com/fwlink/?LinkId=54896
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://homepage.acer.com/...
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://homepage.acer.com/...
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Search_URL = http://go.microsoft.com/fwlink/?LinkId=54896
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Page = http://go.microsoft.com/fwlink/?LinkId=54896
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Start Page = http://homepage.acer.com/...
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,SearchAssistant =
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,CustomizeSearch =
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Local Page = C:\Windows\SysWOW64\blank.htm
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName =
F2 - REG:system.ini: UserInit=userinit.exe
O2 - BHO: HP Print Enhancer - {0347C33E-8762-4905-BF09-768834316C61} - (no file)
O2 - BHO: AcroIEHelperStub - {18DF081C-E8AD-4283-A596-FA578C2EBDC3} - C:\Program Files (x86)\Common Files\Adobe\Acrobat\ActiveX\AcroIEHelperShim.dll
O2 - BHO: Spybot-S&D IE Protection - {53707962-6F74-2D53-2644-206D7942484F} - C:\PROGRA~2\SPYBOT~1\SDHelper.dll
O2 - BHO: OfferBox - {703740c1-0f1a-4cec-a4df-d78db0158477} - C:\Program Files (x86)\OfferBox\extensions-3.1.3878.129\offerbox_air_iexplorer.dll
O2 - BHO: Programme d'aide de l'Assistant de connexion Windows Live ID - {9030D464-4C02-4ABF-8ECC-5164760863C6} - C:\Program Files (x86)\Common Files\Microsoft Shared\Windows Live\WindowsLiveLogin.dll
O2 - BHO: (no name) - {AA58ED58-01DD-4d91-8333-CF10577473F7} - (no file)
O2 - BHO: (no name) - {AF69DE43-7D58-4638-B6FA-CE66B5AD205D} - (no file)
O2 - BHO: Java(tm) Plug-In 2 SSV Helper - {DBC80044-A445-435b-BC74-9C25C1C588A9} - C:\Program Files (x86)\Java\jre6\bin\jp2ssv.dll
O2 - BHO: HP Smart BHO Class - {FFFFFFFF-CF4E-4F2B-BDC2-0E72E116A856} - (no file)
O4 - HKLM\..\Run: [avgnt] "C:\Program Files (x86)\Avira\AntiVir Desktop\avgnt.exe" /min
O4 - HKCU\..\Run: [SpybotSD TeaTimer] C:\Program Files (x86)\Spybot - Search & Destroy\TeaTimer.exe
O4 - HKUS\S-1-5-19\..\Run: [Sidebar] %ProgramFiles%\Windows Sidebar\Sidebar.exe /autoRun (User 'SERVICE LOCAL')
O4 - HKUS\S-1-5-19\..\RunOnce: [mctadmin] C:\Windows\System32\mctadmin.exe (User 'SERVICE LOCAL')
O4 - HKUS\S-1-5-20\..\Run: [Sidebar] %ProgramFiles%\Windows Sidebar\Sidebar.exe /autoRun (User 'SERVICE RÉSEAU')
O4 - HKUS\S-1-5-20\..\RunOnce: [mctadmin] C:\Windows\System32\mctadmin.exe (User 'SERVICE RÉSEAU')
O8 - Extra context menu item: E&xport to Microsoft Excel - res://C:\PROGRA~2\MICROS~3\Office12\EXCEL.EXE/3000
O9 - Extra button: @C:\Program Files (x86)\Windows Live\Writer\WindowsLiveWriterShortcuts.dll,-1004 - {219C3416-8CB2-491a-A3C7-D9FCDDC9D600} - C:\Program Files (x86)\Windows Live\Writer\WriterBrowserExtension.dll
O9 - Extra 'Tools' menuitem: @C:\Program Files (x86)\Windows Live\Writer\WindowsLiveWriterShortcuts.dll,-1003 - {219C3416-8CB2-491a-A3C7-D9FCDDC9D600} - C:\Program Files (x86)\Windows Live\Writer\WriterBrowserExtension.dll
O9 - Extra button: Send to OneNote - {2670000A-7350-4f3c-8081-5663EE0C6C49} - C:\PROGRA~2\MICROS~3\Office12\ONBttnIE.dll
O9 - Extra 'Tools' menuitem: S&end to OneNote - {2670000A-7350-4f3c-8081-5663EE0C6C49} - C:\PROGRA~2\MICROS~3\Office12\ONBttnIE.dll
O9 - Extra button: Research - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - C:\PROGRA~2\MICROS~3\Office12\REFIEBAR.DLL
O9 - Extra button: Afficher ou masquer l'HP Smart Web Printing - {DDE87865-83C5-48c4-8357-2F5B1AA84522} - (no file)
O9 - Extra button: (no name) - {DFB852A3-47F8-48C4-A200-58CAB36FD2A2} - C:\PROGRA~2\SPYBOT~1\SDHelper.dll
O9 - Extra 'Tools' menuitem: Spybot - Search & Destroy Configuration - {DFB852A3-47F8-48C4-A200-58CAB36FD2A2} - C:\PROGRA~2\SPYBOT~1\SDHelper.dll
O10 - Unknown file in Winsock LSP: c:\program files (x86)\common files\microsoft shared\windows live\wlidnsp.dll
O10 - Unknown file in Winsock LSP: c:\program files (x86)\common files\microsoft shared\windows live\wlidnsp.dll
O13 - Gopher Prefix:
O16 - DPF: {C345E174-3E87-4F41-A01C-B066A90A49B4} (WRC Class) - http://trial.trymicrosoftoffice.com/...
O18 - Protocol: wlpg - {E43EF6CD-A37A-4A9B-9E6F-83F89B8E6324} - C:\Program Files (x86)\Windows Live\Photo Gallery\AlbumDownloadProtocolHandler.dll
O23 - Service: @%SystemRoot%\system32\Alg.exe,-112 (ALG) - Unknown owner - C:\Windows\System32\alg.exe (file missing)
O23 - Service: AMD External Events Utility - Unknown owner - C:\Windows\system32\atiesrxx.exe (file missing)
O23 - Service: Avira AntiVir Planificateur (AntiVirSchedulerService) - Avira GmbH - C:\Program Files (x86)\Avira\AntiVir Desktop\sched.exe
O23 - Service: Avira AntiVir Guard (AntiVirService) - Avira GmbH - C:\Program Files (x86)\Avira\AntiVir Desktop\avguard.exe
O23 - Service: Boonty Games - BOONTY - C:\Program Files (x86)\Common Files\BOONTY Shared\Service\Boonty.exe
O23 - Service: @%SystemRoot%\system32\efssvc.dll,-100 (EFS) - Unknown owner - C:\Windows\System32\lsass.exe (file missing)
O23 - Service: Acer ePower Service (ePowerSvc) - Acer Incorporated - C:\Program Files\Acer\Acer ePower Management\ePowerSvc.exe
O23 - Service: @%systemroot%\system32\fxsresm.dll,-118 (Fax) - Unknown owner - C:\Windows\system32\fxssvc.exe (file missing)
O23 - Service: GRegService (Greg_Service) - Acer Incorporated - C:\Program Files (x86)\Acer\Registration\GregHSRW.exe
O23 - Service: @keyiso.dll,-100 (KeyIso) - Unknown owner - C:\Windows\system32\lsass.exe (file missing)
O23 - Service: @comres.dll,-2797 (MSDTC) - Unknown owner - C:\Windows\System32\msdtc.exe (file missing)
O23 - Service: MyWinLocker Service (MWLService) - Egis Technology Inc. - C:\Program Files (x86)\EgisTec\MyWinLocker 3\x86\\MWLService.exe
O23 - Service: @%SystemRoot%\System32\netlogon.dll,-102 (Netlogon) - Unknown owner - C:\Windows\system32\lsass.exe (file missing)
O23 - Service: NTI IScheduleSvc - NewTech Infosystems, Inc. - C:\Program Files (x86)\NewTech Infosystems\Acer Backup Manager\IScheduleSvc.exe
O23 - Service: NTI Backup Now 5 Backup Service (NTIBackupSvc) - NewTech InfoSystems, Inc. - C:\Program Files (x86)\NewTech Infosystems\NTI Backup Now 5\BackupSvc.exe
O23 - Service: NTI Backup Now 5 Scheduler Service (NTISchedulerSvc) - NewTech Infosystems, Inc. - C:\Program Files (x86)\NewTech Infosystems\NTI Backup Now 5\SchedulerSvc.exe
O23 - Service: OfferBox update service - Aedge Performance BCN SL - C:\Program Files (x86)\OfferBox\OfferBoxUpdateService.exe
O23 - Service: @%systemroot%\system32\psbase.dll,-300 (ProtectedStorage) - Unknown owner - C:\Windows\system32\lsass.exe (file missing)
O23 - Service: @%systemroot%\system32\Locator.exe,-2 (RpcLocator) - Unknown owner - C:\Windows\system32\locator.exe (file missing)
O23 - Service: @%SystemRoot%\system32\samsrv.dll,-1 (SamSs) - Unknown owner - C:\Windows\system32\lsass.exe (file missing)
O23 - Service: SBSD Security Center Service (SBSDWSCService) - Safer Networking Ltd. - C:\Program Files (x86)\Spybot - Search & Destroy\SDWinSec.exe
O23 - Service: @%SystemRoot%\system32\snmptrap.exe,-3 (SNMPTRAP) - Unknown owner - C:\Windows\System32\snmptrap.exe (file missing)
O23 - Service: @%systemroot%\system32\spoolsv.exe,-1 (Spooler) - Unknown owner - C:\Windows\System32\spoolsv.exe (file missing)
O23 - Service: @%SystemRoot%\system32\sppsvc.exe,-101 (sppsvc) - Unknown owner - C:\Windows\system32\sppsvc.exe (file missing)
O23 - Service: @%SystemRoot%\system32\ui0detect.exe,-101 (UI0Detect) - Unknown owner - C:\Windows\system32\UI0Detect.exe (file missing)
O23 - Service: Updater Service - Acer - C:\Program Files\Acer\Acer Updater\UpdaterService.exe
O23 - Service: @%SystemRoot%\system32\vaultsvc.dll,-1003 (VaultSvc) - Unknown owner - C:\Windows\system32\lsass.exe (file missing)
O23 - Service: @%SystemRoot%\system32\vds.exe,-100 (vds) - Unknown owner - C:\Windows\System32\vds.exe (file missing)
O23 - Service: @%systemroot%\system32\vssvc.exe,-102 (VSS) - Unknown owner - C:\Windows\system32\vssvc.exe (file missing)
O23 - Service: @%SystemRoot%\system32\Wat\WatUX.exe,-601 (WatAdminSvc) - Unknown owner - C:\Windows\system32\Wat\WatAdminSvc.exe (file missing)
O23 - Service: @%systemroot%\system32\wbengine.exe,-104 (wbengine) - Unknown owner - C:\Windows\system32\wbengine.exe (file missing)
O23 - Servicea: @%Systemroot%\system32\wbem\wmiapsrv.exe,-110 (wmiApSrv) - Unknown owner - C:\Windows\system32\wbem\WmiApSrv.exe (file missing)
O23 - Service: @%PROGRAMFILES%\Windows Media Player\wmpnetwk.exe,-101 (WMPNetworkSvc) - Unknown owner - C:\Program Files (x86)\Windows Media Player\wmpnetwk.exe (file missing)