[Virus]performances tres réduites

Bonjour,
Après échanges sur le forum matériel, mon interlocuteur m'a conseiller de venir sur celui ci.
Mon PC rame depuis 10j environ, il y a des périodes de gel où je n'ai plus de réponses pendant 10 secondes, toutes les minutes.
Je n'arrive pas a quitter Windows proprement, je reste bloquée sur la mire de fermeture et je dois rebooter.
J'ai chargé l'antis virus Avast, le, l'antispyware AVG et le parefeu sunbelt kerio personnam firewall. J'ai détruis 84 fichiers ou mis en quarantaine et 2 trojans (revélés par l'antispyware).
Je pensais avoir juste un pb de mémoire vive mais ca a l'ai plus sérieux !
Quelqu'un peut-il me donner son avis ?? Merci par avance.
Je ne suis pas trés familiarisée avec le jargon des pros, je colle le rapport :

Logfile of HijackThis v1.99.1
Scan saved at 21:36:41, on 17/01/2007
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\svchost.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\system32\spoolsv.exe
C:\Program Files\Alwil Software\Avast4\aswUpdSv.exe
C:\Program Files\Alwil Software\Avast4\ashServ.exe
C:\Program Files\Grisoft\AVG Anti-Spyware 7.5\guard.exe
C:\WINDOWS\System32\drivers\CDAC11BA.EXE
C:\Program Files\Sunbelt Software\Personal Firewall\kpf4ss.exe
C:\WINDOWS\system32\pctspk.exe
C:\WINDOWS\Explorer.EXE
C:\Program Files\Sunbelt Software\Personal Firewall\kpf4gui.exe
C:\Program Files\Alwil Software\Avast4\ashMaiSv.exe
C:\Program Files\Alwil Software\Avast4\ashWebSv.exe
C:\Program Files\Sunbelt Software\Personal Firewall\kpf4gui.exe
C:\Program Files\Adaptec\Easy CD Creator 5\DirectCD\DirectCD.exe
C:\WINDOWS\System32\spool\drivers\w32x86\3\hpztsb04.exe
C:\Program Files\QuickTime\qttask.exe
C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
C:\Program Files\Grisoft\AVG Anti-Spyware 7.5\avgas.exe
C:\WINDOWS\system32\ctfmon.exe
C:\Program Files\Carpe Diem\JF18ans_Sexe\CDUpdater.exe
C:\Program Files\MSN Messenger\MsnMsgr.Exe
C:\Program Files\Hercules\WiFi Station\WifiStation.exe
C:\Documents and Settings\claire\Mes documents\VolumeWatcher\SPUVolumeWatcher.exe
C:\WINDOWS\system32\svchost.exe
C:\Program Files\Internet Explorer\iexplore.exe
C:\Documents and Settings\claire\Local Settings\Temporary Internet Files\Content.IE5\TVGGJECJ\HijackThis[1].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
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Window Title = Microsoft Internet Explorer
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Liens
O2 - BHO: Yahoo! Toolbar Helper - {02478D38-C3F9-4EFB-9B51-7695ECA05670} - C:\Program Files\Yahoo!\Companion\Installs\cpn\yt.dll
O2 - BHO: AcroIEHlprObj Class - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Adobe\Acrobat 5.0\Reader\ActiveX\AcroIEHelper.ocx
O2 - BHO: SponsorAdulto Class - {511F9316-771B-4953-A268-1C36DA667FE9} - C:\WINDOWS\SPONSO~1.DLL (file missing)
O2 - BHO: Windows Live Sign-in Helper - {9030D464-4C02-4ABF-8ECC-5164760863C6} - C:\Program Files\Fichiers communs\Microsoft Shared\Windows Live\WindowsLiveLogin.dll
O3 - Toolbar: Yahoo! Toolbar - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - C:\Program Files\Yahoo!\Companion\Installs\cpn\yt.dll
O4 - HKLM\..\Run: [AdaptecDirectCD] "C:\Program Files\Adaptec\Easy CD Creator 5\DirectCD\DirectCD.exe"
O4 - HKLM\..\Run: [HPDJ Taskbar Utility] C:\WINDOWS\System32\spool\drivers\w32x86\3\hpztsb04.exe
O4 - HKLM\..\Run: [QuickTime Task] "C:\Program Files\QuickTime\qttask.exe" -atboottime
O4 - HKLM\..\Run: [avast!] C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
O4 - HKLM\..\Run: [!AVG Anti-Spyware] "C:\Program Files\Grisoft\AVG Anti-Spyware 7.5\avgas.exe" /minimized
O4 - HKCU\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\ctfmon.exe
O4 - HKCU\..\Run: [CD_Updater] C:\Program Files\Carpe Diem\JF18ans_Sexe\CDUpdater.exe CD_UPDATER
O4 - HKCU\..\Run: [swg] C:\Program Files\Google\GoogleToolbarNotifier\1.2.908.5008\GoogleToolbarNotifier.exe
O4 - HKCU\..\Run: [MsnMsgr] "C:\Program Files\MSN Messenger\MsnMsgr.Exe" /background
O4 - Startup: Outil de détection de support de Cyber-shot Viewer.lnk = C:\Documents and Settings\claire\Mes documents\VolumeWatcher\SPUVolumeWatcher.exe
O4 - Global Startup: WiFi Station.lnk = ?
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
O9 - Extra 'Tools' menuitem: Windows Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\msmsgs.exe
O11 - Options group: [INTERNATIONAL] International*
O12 - Plugin for .pdf: C:\Program Files\Internet Explorer\PLUGINS\nppdf32.dll
O12 - Plugin for .spop: C:\Program Files\Internet Explorer\Plugins\NPDocBox.dll
O14 - IERESET.INF: START_PAGE_URL=https://www.orange.fr/portail
O16 - DPF: {8F48147B-78D9-40F9-ACC0-BDDE59B246F4} (AccountHelper Class) - https://safe.tele2.com/inc/accounthelper.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: WgaLogon - C:\WINDOWS\SYSTEM32\WgaLogon.dll
O23 - Service: avast! iAVS4 Control Service (aswUpdSv) - Unknown owner - C:\Program Files\Alwil Software\Avast4\aswUpdSv.exe
O23 - Service: avast! Antivirus - Unknown owner - 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: AVG Anti-Spyware Guard - Anti-Malware Development a.s. - C:\Program Files\Grisoft\AVG Anti-Spyware 7.5\guard.exe
O23 - Service: C-DillaCdaC11BA - Macrovision - C:\WINDOWS\System32\drivers\CDAC11BA.EXE
O23 - Service: IMAPI CD-Burning COM Service (ImapiService) - Roxio Inc. - C:\WINDOWS\System32\ImapiRox.exe
O23 - Service: Sunbelt Kerio Personal Firewall 4 (KPF4) - Sunbelt Software - C:\Program Files\Sunbelt Software\Personal Firewall\kpf4ss.exe
O23 - Service: PCTEL Speaker Phone (Pctspk) - PCtel, Inc. - C:\WINDOWS\system32\pctspk.exe