Probleme trojan aider moi je suis perdu!

Bonjour,
je suis novice en informatique et j'ai un gros ouscis sur mon ordi après l'avoir prété à mon frère, depuis a chaque fois que je lance une page internet explorer ou le poste de travail j'ai un message "system error : your computer was infected by unknown trojan. It's dangerous for your system (critical files can be lost! CLICK ok to download ...
je me suis un peu balader sur les forum et je n'ai pas de solution.
je suis sur windows vista edition familial avec IE7.
j'ai telecharger hijackthis et l'ai exécuter voici le log si quelqu'un à une idée

Logfile of HijackThis v1.99.1
Scan saved at 19:05:46, on 13/02/2008
Platform: Unknown Windows (WinNT 6.00.1904)
MSIE: Internet Explorer v7.00 (7.00.6000.16609)

Running processes:
C:\Windows\system32\taskeng.exe
C:\Windows\system32\Dwm.exe
C:\Windows\Explorer.EXE
C:\Windows\RtHDVCpl.exe
C:\Program Files\TOSHIBA\Power Saver\TPwrMain.exe
C:\Program Files\TOSHIBA\SmoothView\SmoothView.exe
C:\Program Files\TOSHIBA\FlashCards\TCrdMain.exe
C:\Program Files\TOSHIBA\Registration\ToshibaRegistration.exe
C:\Program Files\Camera Assistant Software for Toshiba\traybar.exe
C:\Program Files\Grisoft\AVG7\avgcc.exe
C:\Program Files\TOSHIBA\TOSCDSPD\TOSCDSPD.exe
C:\Program Files\MSN Messenger\msnmsgr.exe
C:\Program Files\Windows Media Player\wmpnscfg.exe
C:\Program Files\Synaptics\SynTP\SynToshiba.exe
C:\Windows\System32\rundll32.exe
C:\Program Files\Camera Assistant Software for Toshiba\CEC_MAIN.exe
C:\Program Files\MSN Messenger\livecall.exe
C:\Program Files\Internet Explorer\iexplore.exe
C:\Program Files\Internet Explorer\IEUser.exe
C:\Logiciel\HijackThis.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Page = https://www.bing.com/?toHttps=1&redig=5FC791212101479BAFBE1A679848B1AF
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = https://www.google.fr
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 - HKLM\Software\Microsoft\Internet Explorer\Search,SearchAssistant =
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,CustomizeSearch =
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName =
O1 - Hosts: ::1 localhost
O2 - BHO: Adobe PDF Reader Link Helper - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Adobe\Acrobat 7.0\ActiveX\AcroIEHelper.dll
O2 - BHO: SSVHelper Class - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Program Files\Java\jre1.6.0\bin\ssv.dll
O2 - BHO: (no name) - {7E853D72-626A-48EC-A868-BA8D5E23E045} - (no file)
O2 - BHO: Adobe PDF Reader Link Helper - {A8607BAF-0EB3-473C-84C9-F3A5B901A796} - C:\Windows\AcroIEHelper.dll
O4 - HKLM\..\Run: [RtHDVCpl] RtHDVCpl.exe
O4 - HKLM\..\Run: [TPwrMain] %ProgramFiles%\TOSHIBA\Power Saver\TPwrMain.EXE
O4 - HKLM\..\Run: [HSON] %ProgramFiles%\TOSHIBA\TBS\HSON.exe
O4 - HKLM\..\Run: [SmoothView] %ProgramFiles%\Toshiba\SmoothView\SmoothView.exe
O4 - HKLM\..\Run: [00TCrdMain] %ProgramFiles%\TOSHIBA\FlashCards\TCrdMain.exe
O4 - HKLM\..\Run: [HWSetup] C:\Program Files\TOSHIBA\Utilities\HWSetup.exe hwSetUP
O4 - HKLM\..\Run: [SVPWUTIL] C:\Program Files\TOSHIBA\Utilities\SVPWUTIL.exe SVPwUTIL
O4 - HKLM\..\Run: [topi] C:\Program Files\TOSHIBA\Toshiba Online Product Information\topi.exe -startup
O4 - HKLM\..\Run: [NvSvc] RUNDLL32.EXE C:\Windows\system32\nvsvc.dll,nvsvcStart
O4 - HKLM\..\Run: [NvCplDaemon] RUNDLL32.EXE C:\Windows\system32\NvCpl.dll,NvStartup
O4 - HKLM\..\Run: [NvMediaCenter] RUNDLL32.EXE C:\Windows\system32\NvMcTray.dll,NvTaskbarInit
O4 - HKLM\..\Run: [SynTPEnh] C:\Program Files\Synaptics\SynTP\SynTPEnh.exe
O4 - HKLM\..\Run: [Toshiba Registration] C:\Program Files\Toshiba\Registration\ToshibaRegistration.exe
O4 - HKLM\..\Run: [Camera Assistant Software] "C:\Program Files\Camera Assistant Software for Toshiba\traybar.exe"
O4 - HKLM\..\Run: [AVG7_CC] C:\PROGRA~1\Grisoft\AVG7\avgcc.exe /STARTUP
O4 - HKLM\..\Run: [SynTPStart] C:\Program Files\Synaptics\SynTP\SynTPStart.exe
O4 - HKCU\..\Run: [TOSCDSPD] C:\Program Files\TOSHIBA\TOSCDSPD\TOSCDSPD.exe
O4 - HKCU\..\Run: [MsnMsgr] "C:\Program Files\MSN Messenger\MsnMsgr.Exe" /background
O4 - HKCU\..\Run: [WMPNSCFG] C:\Program Files\Windows Media Player\WMPNSCFG.exe
O4 - HKCU\..\Run: [Arovax AntiSpyware] C:\Logiciel\arovax\Arovax AntiSpyware\arovaxantispyware.exe /s
O8 - Extra context menu item: E&xporter vers Microsoft Excel - res://C:\PROGRA~1\MICROS~2\Office12\EXCEL.EXE/3000
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.6.0\bin\npjpi160.dll
O9 - Extra 'Tools' menuitem: Console Java (Sun) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.6.0\bin\npjpi160.dll
O9 - Extra button: Research - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - C:\PROGRA~1\MICROS~2\Office12\REFIEBAR.DLL
O9 - Extra button: eBay - {C08CAF1D-C0A3-40D5-9970-06D067EAC017} - http://www.webtip.ch/cgi-bin/toshiba/tracker_url.pl?FR (file missing)
O10 - Unknown file in Winsock LSP: c:\windows\system32\nlaapi.dll
O10 - Unknown file in Winsock LSP: c:\windows\system32\napinsp.dll
O11 - Options group: [INTERNATIONAL] International*
O13 - Gopher Prefix:
O16 - DPF: {67DABFBF-D0AB-41FA-9C46-CC0F21721616} (DivXBrowserPlugin Object) - http://download.divx.com/player/DivXBrowserPlugin.cab
O16 - DPF: {7DFDB8FD-B498-4958-B930-38021B94351D} (imlUCID Class) - https://validate.perfdrive.com/?ssa=1cb613c1-b580-495b-866c-b6fe71718572&ssb=36371211747&ssc=https%3A%2F%2Fimlive.com%2Fchatsource%2FImlCID.cab&ssi=b98a4b26-ba0f-44c8-a2a5-0315e1e966ee&ssk=support@shieldsquare.com&ssm=77124680964133473105650333749186&ssn=7eafd9fa9826c01597307b85effe791743b46ba2f27a-3977-4b0e-988e66&sso=940ea59d-ee88a13130f2489df365438a8b123fc056d418d499c5df48&ssp=15188465711607082399160702401540426&ssq=67141537474651350705574746278120044759785&ssr=OTEuMjA5LjM1LjIxOA==&sst=Mozilla/5.0%20(X11;%20Linux%20x86_64)%20AppleWebKit/537.36%20(KHTML,%20like%20Gecko)%20Chrome/74.0.3729.131%20Safari/537.36&ssv=&ssw=
O16 - DPF: {D27CDB6E-AE6D-11CF-96B8-444553540000} (Shockwave Flash Object) - http://fpdownload2.macromedia.com/get/shockwave/cabs/flash/swflash.cab
O17 - HKLM\System\CCS\Services\Tcpip\..\{7F7C4701-9A4B-45C6-A6BC-06CF6E47F523}: NameServer = 192.168.112.1
O18 - Protocol: livecall - {828030A1-22C1-4009-854F-8E305202313F} - C:\PROGRA~1\MSNMES~1\MSGRAP~1.DLL
O18 - Protocol: ms-help - {314111C7-A502-11D2-BBCA-00C04F8EC294} - C:\Program Files\Common Files\Microsoft Shared\Help\hxds.dll
O18 - Protocol: msnim - {828030A1-22C1-4009-854F-8E305202313F} - C:\PROGRA~1\MSNMES~1\MSGRAP~1.DLL
O18 - Filter hijack: text/xml - {807563E5-5146-11D5-A672-00B0D022E945} - C:\PROGRA~1\COMMON~1\MICROS~1\OFFICE12\MSOXMLMF.DLL
O20 - Winlogon Notify: avgwlntf - C:\Windows\SYSTEM32\avgwlntf.dll
O23 - Service: AVG7 Alert Manager Server (Avg7Alrt) - GRISOFT, s.r.o. - C:\PROGRA~1\Grisoft\AVG7\avgamsvr.exe
O23 - Service: AVG7 Update Service (Avg7UpdSvc) - GRISOFT, s.r.o. - C:\PROGRA~1\Grisoft\AVG7\avgupsvc.exe
O23 - Service: AVG7 Resident Shield Service (AvgCoreSvc) - GRISOFT, s.r.o. - C:\PROGRA~1\Grisoft\AVG7\avgrssvc.exe
O23 - Service: AVG E-mail Scanner (AVGEMS) - GRISOFT, s.r.o. - C:\PROGRA~1\Grisoft\AVG7\avgemc.exe
O23 - Service: Symantec Lic NetConnect service (CLTNetCnService) - Unknown owner - C:\Program Files\Common Files\Symantec Shared\ccSvcHst.exe" /h ccCommon (file missing)
O23 - Service: @%SystemRoot%\ehome\ehstart.dll,-101 (ehstart) - Unknown owner - %windir%\system32\svchost.exe (file missing)
O23 - Service: @%SystemRoot%\system32\qwave.dll,-1 (QWAVE) - Unknown owner - %windir%\system32\svchost.exe (file missing)
O23 - Service: @%SystemRoot%\system32\seclogon.dll,-7001 (seclogon) - Unknown owner - %windir%\system32\svchost.exe (file missing)
O23 - Service: TOSHIBA Optical Disc Drive Service (TODDSrv) - TOSHIBA Corporation - C:\Windows\system32\TODDSrv.exe
O23 - Service: TOSHIBA Power Saver (TosCoSrv) - TOSHIBA Corporation - C:\Program Files\TOSHIBA\Power Saver\TosCoSrv.exe
O23 - Service: TOSHIBA Bluetooth Service - TOSHIBA CORPORATION - c:\Program Files\Toshiba\Bluetooth Toshiba Stack\TosBtSrv.exe
O23 - Service: Ulead Burning Helper (UleadBurningHelper) - Ulead Systems, Inc. - C:\Program Files\Common Files\Ulead Systems\DVD\ULCDRSvr.exe
O23 - Service: @%ProgramFiles%\Windows Media Player\wmpnetwk.exe,-101 (WMPNetworkSvc) - Unknown owner - %ProgramFiles%\Windows Media Player\wmpnetwk.exe (file missing)