Comment désinstaller antivirus XP ?

Bonjour,

Je ne sais pas comment me débarrasser de l'antivirus XP 2008.voici le rapport généré par Hijack mais je suis inexpérimentée en informatique et je ne sais pas quoi en faire. De plus mon ordinateur a tendance à redémarrer après l'avoir éteint.
Que faire pour éliminer définitivement l'antivirus XP ? Merci pour vos conseils.

Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 22:43:06, on 07/09/2008
Platform: Windows XP SP2 (WinNT 5.01.2600)
MSIE: Internet Explorer v7.00 (7.00.6000.16705)
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\svchost.exe
C:\Program Files\Windows Defender\MsMpEng.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:\Program Files\Google\Common\Google Updater\GoogleUpdaterService.exe
C:\WINDOWS\system32\CNAB4RPK.EXE
C:\Program Files\Alwil Software\Avast4\ashMaiSv.exe
C:\Program Files\Alwil Software\Avast4\ashWebSv.exe
C:\WINDOWS\Explorer.EXE
C:\Program Files\BillP Studios\WinPatrol\winpatrol.exe
C:\Program Files\rhcr1cj0er1q\rhcr1cj0er1q.exe
C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
C:\WINDOWS\system32\ctfmon.exe
C:\Program Files\Messenger\msmsgs.exe
C:\Program Files\Google\GoogleToolbarNotifier\GoogleToolbarNotifier.exe
C:\WINDOWS\system32\sistray.exe
C:\WINDOWS\system32\spool\drivers\w32x86\3\CNAB4LAK.EXE
C:\Program Files\OpenOffice.org 2.4\program\soffice.exe
C:\Program Files\OpenOffice.org 2.4\program\soffice.BIN
C:\WINDOWS\system32\pphcv1cj0er1q.exe
C:\Program Files\Mozilla Firefox\firefox.exe
C:\PROGRA~1\Crawler\Toolbar\CToolbar.exe
C:\WINDOWS\system32\rundll32.exe
C:\Program Files\Trend Micro\HijackThis\HijackThis.exe

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 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Liens
O2 - BHO: AcroIEHelperStub - {18DF081C-E8AD-4283-A596-FA578C2EBDC3} - C:\Program Files\Fichiers communs\Adobe\Acrobat\ActiveX\AcroIEHelperShim.dll
O2 - BHO: (no name) - {1CB20BF0-BBAE-40A7-93F4-6435FF3D0411} - C:\PROGRA~1\Crawler\Toolbar\ctbr.dll
O2 - BHO: SSVHelper Class - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Program Files\Java\jre1.6.0_07\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\2.1.1119.1736\swg.dll
O3 - Toolbar: &Google - {2318C2B1-4965-11d4-9B18-009027A5CD4F} - c:\program files\google\googletoolbar2.dll
O3 - Toolbar: Barre d'outils &Crawler - {4B3803EA-5230-4DC3-A7FC-33638F3D3542} - C:\PROGRA~1\Crawler\Toolbar\ctbr.dll
O3 - Toolbar: FireShot - {6E6E744E-4D20-4ce3-9A7A-26DFFFE22F68} - C:\Documents and Settings\Isabelle Kabouche\Application Data\Mozilla\Firefox\Profiles\go8qft9i.default\extensions\{0b457cAA-602d-484a-8fe7-c1d894a011ba}\library\fsaddin-0.58.dll
O4 - HKLM\..\Run: [WinPatrol] C:\Program Files\BillP Studios\WinPatrol\winpatrol.exe -expressboot
O4 - HKLM\..\Run: [SMrhcr1cj0er1q] C:\Program Files\rhcr1cj0er1q\rhcr1cj0er1q.exe
O4 - HKLM\..\Run: [avast!] C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
O4 - HKCU\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\ctfmon.exe
O4 - HKCU\..\Run: [MSMSGS] "C:\Program Files\Messenger\msmsgs.exe" /background
O4 - HKCU\..\Run: [swg] C:\Program Files\Google\GoogleToolbarNotifier\GoogleToolbarNotifier.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')
O4 - Startup: OpenOffice.org 2.4.lnk = C:\Program Files\OpenOffice.org 2.4\program\quickstart.exe
O4 - Global Startup: Utility Tray.lnk = C:\WINDOWS\system32\sistray.exe
O4 - Global Startup: Canon LBP2900 Fenêtre d'état.lnk = C:\WINDOWS\system32\spool\drivers\w32x86\3\CNAB4LAK.EXE
O8 - Extra context menu item: Crawler Search - tbr:iemenu
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.6.0_07\bin\ssv.dll
O9 - Extra 'Tools' menuitem: Console Java (Sun) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.6.0_07\bin\ssv.dll
O9 - Extra button: (no name) - {e2e2dd38-d088-4134-82b7-f2ba38496583} - C:\WINDOWS\Network Diagnostic\xpnetdiag.exe
O9 - Extra 'Tools' menuitem: @xpsp3res.dll,-20001 - {e2e2dd38-d088-4134-82b7-f2ba38496583} - C:\WINDOWS\Network Diagnostic\xpnetdiag.exe
O9 - Extra button: Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\msmsgs.exe
O9 - Extra 'Tools' menuitem: Windows Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\msmsgs.exe
O18 - Protocol: tbr - {4D25FB7A-8902-4291-960E-9ADA051CFBBF} - C:\PROGRA~1\Crawler\Toolbar\ctbr.dll
O23 - Service: avast! iAVS4 Control Service (aswUpdSv) - ALWIL Software - C:\Program Files\Alwil Software\Avast4\aswUpdSv.exe
O23 - Service: avast! Antivirus - ALWIL Software - C:\Program Files\Alwil Software\Avast4\ashServ.exe
O23 - Service: avast! Mail Scanner - ALWIL Software - C:\Program Files\Alwil Software\Avast4\ashMaiSv.exe
O23 - Service: avast! Web Scanner - ALWIL Software - C:\Program Files\Alwil Software\Avast4\ashWebSv.exe
O23 - Service: Google Updater Service (gusvc) - Google - C:\Program Files\Google\Common\Google Updater\GoogleUpdaterService.exe