Ces derniers temps toute les clé usb que je met dans mon pc apparait avec des virus et ce ne sais pas quoi faire je l´ai analise avec antivir et aucun virus apparait

ci joint je vous envoie un rapport hijackthis
merci d´avance
Logfile of Trend Micro HijackThis v2.0.4
Scan saved at 14:40:17, on 28-11-2010
Platform: Windows Vista SP2 (WinNT 6.00.1906)
MSIE: Internet Explorer v8.00 (8.00.6001.18975)
Boot mode: Normal
Running processes:
C:\Windows\system32\Dwm.exe
C:\Windows\system32\taskeng.exe
C:\Windows\system32\taskeng.exe
C:\Program Files\Hotkey_Driver\HotkeyDriver.exe
C:\Windows\system32\wbem\unsecapp.exe
C:\Windows\system32\conime.exe
C:\Windows\explorer.exe
C:\Program Files\sapo internet movel\UIMain.exe
C:\Windows\System32\mobsync.exe
C:\Program Files\Windows Media Player\wmpnscfg.exe
C:\Users\tmn\AppData\Local\Google\Chrome\Application\chrome.exe
C:\Users\tmn\AppData\Local\Google\Chrome\Application\chrome.exe
C:\Users\tmn\AppData\Local\Google\Chrome\Application\chrome.exe
C:\Users\tmn\Desktop\HiJackThis.exe
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Start Page = http://fr.msn.com/
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,SearchAssistant =
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,CustomizeSearch =
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Window Title = Windows Internet Explorer
O4 - HKLM\..\Run: [SynTPStart] C:\Program Files\Synaptics\SynTP\SynTPStart.exe
O4 - HKLM\..\Run: [avgnt] "C:\Program Files\Avira\AntiVir Desktop\avgnt.exe" /min
O4 - HKCU\..\Run: [msnmsgr] "C:\Program Files\Windows Live\Messenger\msnmsgr.exe" /background
O9 - Extra button: @C:\Program Files\Windows Live\Writer\WindowsLiveWriterShortcuts.dll,-1004 - {219C3416-8CB2-491a-A3C7-D9FCDDC9D600} - C:\Program Files\Windows Live\Writer\WriterBrowserExtension.dll
O9 - Extra 'Tools' menuitem: @C:\Program Files\Windows Live\Writer\WindowsLiveWriterShortcuts.dll,-1003 - {219C3416-8CB2-491a-A3C7-D9FCDDC9D600} - C:\Program Files\Windows Live\Writer\WriterBrowserExtension.dll
O17 - HKLM\System\CCS\Services\Tcpip\..\{37D04C29-50A8-483C-9BE7-FAD839751046}: NameServer = 88.214.178.2 88.214.182.1
O17 - HKLM\System\CS1\Services\Tcpip\..\{37D04C29-50A8-483C-9BE7-FAD839751046}: NameServer = 88.214.178.2 88.214.182.1
O18 - Protocol: wlpg - {E43EF6CD-A37A-4A9B-9E6F-83F89B8E6324} - C:\Program Files\Windows Live\Photo Gallery\AlbumDownloadProtocolHandler.dll
O22 - SharedTaskScheduler: Component Categories cache daemon - {8C7461EF-2B13-11d2-BE35-3078302C2030} - C:\Windows\system32\browseui.dll
O23 - Service: Avira AntiVir Scheduler (AntiVirSchedulerService) - Avira GmbH - C:\Program Files\Avira\AntiVir Desktop\sched.exe
O23 - Service: Avira AntiVir Guard (AntiVirService) - Avira GmbH - C:\Program Files\Avira\AntiVir Desktop\avguard.exe
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End of file - 2625 bytes