Problème d'anti virus

Bonjour,

J'ai un problème avec mon antivirus avast. je ne peux plus l'installer.
Effectivement, j'ai détecté 3 logiciels qui me bloque.
F-Secure Anti-Virus
F-Secure Management Agent
Securitoo AntiVirus Firewall
Ils se sont installés tout seul sur mon pc.
J'ai fais une analyse Hijackthis. Je vous envoie le rapport.
D'autre part , des publicités intempestives n'arrêtent d'arriver.

Que dois-je faire.
Je suis débutant en la matière.
Merci
Bien cordialement
Bagatelle

Logfile of HijackThis v1.99.1
Scan saved at 10:49:05, on 15/06/2007
Platform: Windows XP SP2 (WinNT 5.01.2600)
MSIE: Internet Explorer v6.00 SP2 (6.00.2900.2180)

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:\WINDOWS\System32\svchost.exe
C:\WINDOWS\Explorer.EXE
C:\WINDOWS\system32\spoolsv.exe
C:\Program Files\QuickTime\qttask.exe
C:\Program Files\Grisoft\AVG Anti-Spyware 7.5\avgas.exe
C:\Program Files\MSN Messenger\msnmsgr.exe
C:\Program Files\Messenger\MSMSGS.EXE
C:\Program Files\MessengerSkinner\MessengerSkinner.exe
C:\WINDOWS\FSScrCtl.exe
C:\Program Files\Grisoft\AVG Anti-Spyware 7.5\guard.exe
C:\PROGRA~1\SECURI~1\8520111\Program\SERVIC~1.EXE
C:\Program Files\F-Secure\Anti-Virus\fsgk32st.exe
C:\Program Files\Securitoo AntiVirus\8520111\program\fsbwsys.exe
C:\Program Files\F-Secure\Anti-Virus\FSGK32.EXE
C:\Program Files\Securitoo AntiVirus\8520111\Program\fspex.exe
C:\Program Files\F-Secure\Common\FSMA32.EXE
C:\Program Files\F-Secure\Anti-Virus\fssm32.exe
C:\Program Files\F-Secure\Common\FSMB32.EXE
C:\Program Files\F-Secure\Common\FCH32.EXE
C:\Program Files\F-Secure\Common\FAMEH32.EXE
C:\Program Files\F-Secure\FWES\Program\fsdfwd.exe
C:\WINDOWS\system32\wscntfy.exe
C:\Program Files\F-Secure\Anti-Virus\fsav32.exe
C:\Program Files\Fichiers communs\Microsoft Shared\Windows Live\WLLoginProxy.exe
C:\WINDOWS\System32\svchost.exe
C:\Program Files\Internet Explorer\iexplore.exe
C:\Program Files\Hijackthis Version Française\hijackthis vf.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Bar = https://www.bing.com/?cc=fr&toHttps=1&redig=D4322FEE7CF74A348CB9CE970F098EF5
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = https://www.msn.com/fr-fr
R1 - HKCU\Software\Microsoft\Internet Explorer\SearchURL,(Default) = https://www.bing.com/?FORM=TOOLBR&cc=fr&toHttps=1&redig=4527FFF1C12746FC9EDB535C75E80ECC
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Liens
O2 - BHO: AcroIEHlprObj Class - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Apps\Adobe\Acrobat 5.1\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: Windows Live Toolbar Helper - {BDBD1DAD-C946-4A17-ADC1-64B5B4FF55D0} - C:\Program Files\Windows Live Toolbar\msntb.dll
O3 - Toolbar: Windows Live Toolbar - {BDAD1DAD-C946-4A17-ADC1-64B5B4FF55D0} - C:\Program Files\Windows Live Toolbar\msntb.dll
O4 - HKLM\..\Run: [QuickTime Task] "C:\Program Files\QuickTime\qttask.exe" -atboottime
O4 - HKLM\..\Run: [Spyware-Secure] C:\Program Files\Spyware-Secure\Spyware-Secure_trial.exe
O4 - HKLM\..\Run: [KernelFaultCheck] %systemroot%\system32\dumprep 0 -k
O4 - HKLM\..\Run: [Salestart] "C:\Program Files\Fichiers communs\WinAntiVirus Pro 2007\mav_startupmon.exe"
O4 - HKLM\..\Run: [!AVG Anti-Spyware] "C:\Program Files\Grisoft\AVG Anti-Spyware 7.5\avgas.exe" /minimized
O4 - HKCU\..\Run: [msnmsgr] "C:\Program Files\MSN Messenger\msnmsgr.exe" /background
O4 - HKCU\..\Run: [MSMSGS] "C:\Program Files\Messenger\MSMSGS.EXE" /background
O4 - HKCU\..\Run: [MailSkinner] c:\program files\mailskinner\mailskinner.exe
O4 - HKCU\..\Run: [ErrorSafeFree] "C:\Program Files\ErrorSafe Free\uers.exe" /min
O4 - HKCU\..\Run: [messengerskinner] C:\Program Files\MessengerSkinner\MessengerSkinner.exe
O4 - Startup: Screen Saver Control.lnk = C:\WINDOWS\FSScrCtl.exe
O4 - Global Startup: Event Reminder.lnk = C:\Program Files\Broderbund\PrintMaster\PMremind.exe
O8 - Extra context menu item: &Windows Live Search - res://C:\Program Files\Windows Live Toolbar\msntb.dll/search.htm
O9 - Extra button: Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\MSMSGS.EXE
O9 - Extra 'Tools' menuitem: Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\MSMSGS.EXE
O16 - DPF: {1D6E056F-D1BB-40F6-88E4-11EE98056FD2} (Oberon ActiveX Game Host) - http://jeuxenligne-beta.jeu.orange.fr/Gameshell/GameHost/1.0/OberonGameHost.cab
O16 - DPF: {5ED80217-570B-4DA9-BF44-BE107C0EC166} (Windows Live Safety Center Base Module) - http://cdn.scan.onecare.live.com/resource/download/scanner/wlscbase9602.cab
O16 - DPF: {DF780F87-FF2B-4DF8-92D0-73DB16A1543A} (PopCapLoader Object) - file://C:\Documents and Settings\p1\Local Settings\Application Data\Oberon Media\Oberon Games Host\popcaploader_v6.cab
O18 - Protocol: livecall - {828030A1-22C1-4009-854F-8E305202313F} - C:\PROGRA~1\MSNMES~1\MSGRAP~1.DLL
O18 - Protocol: msnim - {828030A1-22C1-4009-854F-8E305202313F} - C:\PROGRA~1\MSNMES~1\MSGRAP~1.DLL
O20 - Winlogon Notify: igfxcui - C:\WINDOWS\SYSTEM32\igfxsrvc.dll
O20 - Winlogon Notify: WgaLogon - C:\WINDOWS\SYSTEM32\WgaLogon.dll
O21 - SSODL: WPDShServiceObj - {AAA288BA-9A4C-45B0-95D7-94D524869DB5} - C:\WINDOWS\system32\WPDShServiceObj.dll
O23 - Service: AVG Anti-Spyware Guard - GRISOFT s.r.o. - C:\Program Files\Grisoft\AVG Anti-Spyware 7.5\guard.exe
O23 - Service: Securitoo Antivirus Firewall (BackWeb Plug-in - 8520111) - Unknown owner - C:\PROGRA~1\SECURI~1\8520111\Program\SERVIC~1.EXE
O23 - Service: Boonty Games - BOONTY - C:\Program Files\Fichiers communs\BOONTY Shared\Service\Boonty.exe
O23 - Service: F-Secure Gatekeeper Handler Starter - F-Secure Corp. - C:\Program Files\F-Secure\Anti-Virus\fsgk32st.exe
O23 - Service: fsbwsys - F-Secure Corp. - C:\Program Files\Securitoo AntiVirus\8520111\program\fsbwsys.exe
O23 - Service: F-Secure Anti-Virus Firewall Daemon (FSDFWD) - F-Secure Corporation - C:\Program Files\F-Secure\FWES\Program\fsdfwd.exe
O23 - Service: FSMA - F-Secure Corporation - C:\Program Files\F-Secure\Common\FSMA32.EXE
O23 - Service: OracleOraHome81ClientCache - Unknown owner - C:\oracle\ora81\BIN\ONRSD.EXE (file missing)