Problemme de viruse

Bonjour,
slt a ts jé besoin d'aide je travaille dons un cyber et mes postes le son se desactive tt seul,windows media player ne lire pas la musique et le reseau devien lent alor je suis perdu esquil ya quelle qu'en qui peut me donné une solution stp et merci avance

Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 20:54:09, on 11/08/2009
Platform: Windows XP SP2 (WinNT 5.01.2600)
MSIE: Internet Explorer v6.00 SP2 (6.00.2900.2180)
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:\Program Files\HyperTechnologies\Deep Freeze\DfServEx.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:\Program Files\HyperTechnologies\Deep Freeze\_$Df\FrzState.exe
C:\WINDOWS\system32\spoolsv.exe
C:\Program Files\Java\jre6\bin\jqs.exe
C:\WINDOWS\system32\svchost.exe
C:\Program Files\Yahoo!\SoftwareUpdate\YahooAUService.exe
C:\WINDOWS\Explorer.EXE
C:\Program Files\Alwil Software\Avast4\ashMaiSv.exe
C:\Program Files\Alwil Software\Avast4\ashWebSv.exe
C:\WINDOWS\system32\wbem\wmiapsrv.exe
C:\WINDOWS\system32\igfxtray.exe
C:\WINDOWS\system32\hkcmd.exe
C:\WINDOWS\system32\igfxpers.exe
C:\Program Files\Fichiers communs\Real\Update_OB\realsched.exe
C:\Program Files\Java\jre6\bin\jusched.exe
C:\WINDOWS\VM303_STI.EXE
C:\WINDOWS\system32\igfxsrvc.exe
C:\PROGRA~1\TinaSoft\EASYCA~1\client.exe
C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
C:\WINDOWS\system32\ctfmon.exe
C:\Program Files\Messenger\msmsgs.exe
C:\PROGRA~1\TinaSoft\EASYCA~1\Guardit.exe
C:\Program Files\Mozilla Firefox\firefox.exe
C:\Program Files\Windows Live\Messenger\msnmsgr.exe
C:\Program Files\Windows Live\Contacts\wlcomm.exe
C:\Program Files\Internet Explorer\IEXPLORE.EXE
C:\Program Files\Skype\Phone\Skype.exe
C:\Program Files\Skype\Plugin Manager\skypePM.exe
C:\Documents and Settings\poste\Bureau\HiJackThis.exe

R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = about:blank
R1 - HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings,ProxyOverride = http://192.168.1.111:918
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Liens
R3 - URLSearchHook: Yahoo! Toolbar - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - C:\PROGRA~1\Yahoo!\Companion\Installs\cpn\yt.dll
O2 - BHO: &Yahoo! Toolbar Helper - {02478D38-C3F9-4efb-9B51-7695ECA05670} - C:\PROGRA~1\Yahoo!\Companion\Installs\cpn\yt.dll
O2 - BHO: AcroIEHelperStub - {18DF081C-E8AD-4283-A596-FA578C2EBDC3} - C:\Program Files\Fichiers communs\Adobe\Acrobat\ActiveX\AcroIEHelperShim.dll
O2 - BHO: Skype add-on (mastermind) - {22BF413B-C6D2-4d91-82A9-A0F997BA588C} - C:\Program Files\Skype\Toolbars\Internet Explorer\SkypeIEPlugin.dll
O2 - BHO: RealPlayer Download and Record Plugin for Internet Explorer - {3049C3E9-B461-4BC5-8870-4C09146192CA} - C:\Program Files\Real\RealPlayer\rpbrowserrecordplugin.dll
O2 - BHO: (no name) - {5C255C8A-E604-49b4-9D64-90988571CECB} - (no file)
O2 - BHO: Programme d'aide de l'Assistant de connexion Windows Live - {9030D464-4C02-4ABF-8ECC-5164760863C6} - C:\Program Files\Fichiers communs\Microsoft Shared\Windows Live\WindowsLiveLogin.dll
O2 - BHO: Java(tm) Plug-In 2 SSV Helper - {DBC80044-A445-435b-BC74-9C25C1C588A9} - C:\Program Files\Java\jre6\bin\jp2ssv.dll
O2 - BHO: JQSIEStartDetectorImpl - {E7E6F031-17CE-4C07-BC86-EABFE594F69C} - C:\Program Files\Java\jre6\lib\deploy\jqs\ie\jqs_plugin.dll
O2 - BHO: SingleInstance Class - {FDAD4DA1-61A2-4FD8-9C17-86F7AC245081} - C:\PROGRA~1\Yahoo!\Companion\Installs\cpn\YTSingleInstance.dll
O3 - Toolbar: Yahoo! Toolbar - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - C:\PROGRA~1\Yahoo!\Companion\Installs\cpn\yt.dll
O4 - HKLM\..\Run: [IgfxTray] C:\WINDOWS\system32\igfxtray.exe
O4 - HKLM\..\Run: [HotKeysCmds] C:\WINDOWS\system32\hkcmd.exe