Pc qui rame et defragmentation impossible

bonsoir a tous,
mon pc rame enormement et je ne peux plus faire de défragmentation (ni windows, ni perfectdisk).
On m'a dit que c'étais surement du a un virus, alors voici mon raport hijackthis en vous remerciant pour votre aide!!!
Logfile of HijackThis v1.99.1
Scan saved at 22:25:38, on 26/05/2007
Platform: Windows XP SP2 (WinNT 5.01.2600)
MSIE: Internet Explorer v7.00 (7.00.5730.0011)

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:\Program Files\Alwil Software\Avast4\aswUpdSv.exe
C:\Program Files\Alwil Software\Avast4\ashServ.exe
C:\WINDOWS\system32\spoolsv.exe
C:\WINDOWS\Explorer.EXE
C:\Program Files\Google\Common\Google Updater\GoogleUpdaterService.exe
C:\WINDOWS\System32\svchost.exe
C:\Program Files\Raxco\PerfectDisk\PDSched.exe
C:\Program Files\Google\Gmail Notifier\gnotify.exe
C:\Program Files\Alwil Software\Avast4\ashMaiSv.exe
C:\Program Files\Java\jre1.6.0_01\bin\jusched.exe
C:\WINDOWS\SOUNDMAN.EXE
C:\Program Files\Alwil Software\Avast4\ashWebSv.exe
C:\Program Files\QuickTime\qttask.exe
C:\Program Files\iTunes\iTunesHelper.exe
C:\Program Files\HP\HP Software Update\HPWuSchd2.exe
C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
C:\WINDOWS\system32\ctfmon.exe
C:\Program Files\Internet Explorer\iexplore.exe
C:\Program Files\iPod\bin\iPodService.exe
C:\Program Files\Google\Google Updater\GoogleUpdater.exe
C:\Program Files\HP\Digital Imaging\bin\hpqtra08.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\system32\wuauclt.exe
C:\Program Files\HP\Digital Imaging\bin\hpqSTE08.exe
C:\WINDOWS\system32\HPZipm12.exe
C:\Program Files\HP\Digital Imaging\bin\hpqimzone.exe
C:\WINDOWS\system32\wuauclt.exe
C:\PROGRA~2\IZARC\IZARC.EXE
C:\DOCUME~1\NICOLAS\LOCALS~1\Temp\ARC10\HijackThis.exe

R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = https://www.google.fr/?gws_rd=ssl
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 Bar = http://home.fr.netscape.com/fr/home/winsearch200.html
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 = https://actus.sfr.fr
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Liens
O2 - BHO: Aide pour le lien d'Adobe PDF Reader - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Fichiers communs\Adobe\Acrobat\ActiveX\AcroIEHelper.dll
O2 - BHO: metaspinner media GmbH - {12FC9A49-CFE0-49AA-BE9E-8F4EEAFC9443} - C:\PROGRA~1\YETISP~1\IEBUTT~1.DLL
O2 - BHO: EoRezoBHO - {64F56FC1-1272-44CD-BA6E-39723696E350} - (no file)
O2 - BHO: SSVHelper Class - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Program Files\Java\jre1.6.0_01\bin\ssv.dll
O2 - BHO: Google Toolbar Helper - {AA58ED58-01DD-4d91-8333-CF10577473F7} - c:\program files\google\googletoolbar2.dll
O2 - BHO: Google Toolbar Notifier BHO - {AF69DE43-7D58-4638-B6FA-CE66B5AD205D} - C:\Program Files\Google\GoogleToolbarNotifier\2.0.301.5672\swg.dll
O3 - Toolbar: (no name) - {BA52B914-B692-46c4-B683-905236F6F655} - (no file)
O3 - Toolbar: &Google - {2318C2B1-4965-11d4-9B18-009027A5CD4F} - c:\program files\google\googletoolbar2.dll
O4 - HKLM\..\Run: [{0228e555-4f9c-4e35-a3ec-b109a192b4c2}] C:\Program Files\Google\Gmail Notifier\gnotify.exe
O4 - HKLM\..\Run: [SunJavaUpdateSched] "C:\Program Files\Java\jre1.6.0_01\bin\jusched.exe"
O4 - HKLM\..\Run: [SoundMan] SOUNDMAN.EXE
O4 - HKLM\..\Run: [QuickTime Task] "C:\Program Files\QuickTime\qttask.exe" -atboottime
O4 - HKLM\..\Run: [Logitech Hardware Abstraction Layer] KHALMNPR.EXE
O4 - HKLM\..\Run: [iTunesHelper] "C:\Program Files\iTunes\iTunesHelper.exe"
O4 - HKLM\..\Run: [HP Software Update] C:\Program Files\HP\HP Software Update\HPWuSchd2.exe
O4 - HKLM\..\Run: [avast!] C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
O4 - HKCU\..\Run: [swg] C:\Program Files\Google\GoogleToolbarNotifier\GoogleToolbarNotifier.exe
O4 - HKCU\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\ctfmon.exe
O4 - Global Startup: Outil de mise à jour Google.lnk = C:\Program Files\Google\Google Updater\GoogleUpdater.exe
O4 - Global Startup: Démarrage rapide du logiciel HP Image Zone.lnk = C:\Program Files\HP\Digital Imaging\bin\hpqthb08.exe
O4 - Global Startup: Lancement rapide d'Adobe Reader.lnk = C:\Program Files\Adobe\Reader 8.0\Reader\reader_sl.exe
O4 - Global Startup: HP Digital Imaging Monitor.lnk = C:\Program Files\HP\Digital Imaging\bin\hpqtra08.exe
O4 - Global Startup: Adobe Reader Synchronizer.lnk = C:\Program Files\Adobe\Reader 8.0\Reader\AdobeCollabSync.exe
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.6.0_01\bin\ssv.dll
O9 - Extra 'Tools' menuitem: Console Java (Sun) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.6.0_01\bin\ssv.dll
O9 - Extra button: (no name) - {CD67F990-D8E9-11d2-98FE-00C0F0318AFE} - (no file)
O9 - Extra button: (no name) - {e2e2dd38-d088-4134-82b7-f2ba38496583} - %windir%\Network Diagnostic\xpnetdiag.exe (file missing)
O9 - Extra 'Tools' menuitem: @xpsp3res.dll,-20001 - {e2e2dd38-d088-4134-82b7-f2ba38496583} - %windir%\Network Diagnostic\xpnetdiag.exe (file missing)
O9 - Extra button: Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\msmsgs.exe (file missing)
O9 - Extra 'Tools' menuitem: Windows Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\msmsgs.exe (file missing)
O11 - Options group: [INTERNATIONAL] International*
O14 - IERESET.INF: START_PAGE_URL=https://www.acer.com/worldwide/selection.html
O16 - DPF: {49232000-16E4-426C-A231-62846947304B} (SysData Class) - http://ipgweb.cce.hp.com/rdqemea/downloads/sysinfo.cab
O16 - DPF: {4ED9DDF0-7479-4BBE-9335-5A1EDB1D8A21} - http://download.av.fr.aol.com/molbin/shared/mcinsctl/fr/4,0,0,84/mcinsctl.cab
O16 - DPF: {92E7E45A-D8C8-480E-AF99-176E43997CAA} (Aurigma Image Uploader 3.5 Combo Control) - http://www.pixdiscount.fr/clients/ImageUploader3.cab
O16 - DPF: {9A9307A0-7DA4-4DAF-B042-5009F29E09E1} (ActiveScan Installer Class) - http://acs.pandasoftware.com/activescan/as5free/asinst.cab
O16 - DPF: {BCC0FF27-31D9-4614-A68E-C18E1ADA4389} - http://download.av.fr.aol.com/molbin/shared/mcgdmgr/fr/1,0,0,21/mcgdmgr.cab
O16 - DPF: {D27CDB6E-AE6D-11CF-96B8-444553540000} (Shockwave Flash Object) - http://fpdownload2.macromedia.com/get/shockwave/cabs/flash/swflash.cab
O20 - Winlogon Notify: WgaLogon - C:\WINDOWS\SYSTEM32\WgaLogon.dll
O21 - SSODL: WPDShServiceObj - {AAA288BA-9A4C-45B0-95D7-94D524869DB5} - C:\WINDOWS\system32\WPDShServiceObj.dll
O23 - Service: avast! iAVS4 Control Service (aswUpdSv) - ALWIL Software - C:\Program Files\Alwil Software\Avast4\aswUpdSv.exe
O23 - Service: Ati HotKey Poller - Unknown owner - C:\WINDOWS\System32\Ati2evxx.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: Google Updater Service (gusvc) - Google - C:\Program Files\Google\Common\Google Updater\GoogleUpdaterService.exe
O23 - Service: InstallDriver Table Manager (IDriverT) - Macrovision Corporation - C:\Program Files\Fichiers communs\InstallShield\Driver\11\Intel 32\IDriverT.exe
O23 - Service: Service de l'iPod (iPod Service) - Apple Computer, Inc. - C:\Program Files\iPod\bin\iPodService.exe
O23 - Service: iPodService - Apple Computer, Inc. - C:\Program Files\iPod\bin\iPodService.exe
O23 - Service: PDEngine - Raxco Software, Inc. - C:\Program Files\Raxco\PerfectDisk\PDEngine.exe
O23 - Service: PDScheduler (PDSched) - Raxco Software, Inc. - C:\Program Files\Raxco\PerfectDisk\PDSched.exe
O23 - Service: Pml Driver HPZ12 - HP - C:\WINDOWS\system32\HPZipm12.exe