Grazie Alfonso ecco il log, ne avevo fatto uno neanche una settimana fa me essere prudenti è meglio <img src=icon_smile.gif border=0 align=middle>

Logfile of HijackThis v1.99.1
Scan saved at 18.37.42, on 19/07/2005
Platform: Windows XP (WinNT 5.01.2600)
MSIE: Internet Explorer v6.00 SP1 (6.00.2600.0000)

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:\Programmi\File comuni\Symantec Shared\ccSetMgr.exe
C:\Programmi\File comuni\Symantec Shared\SNDSrvc.exe
C:\WINDOWS\Explorer.EXE
C:\Programmi\File comuni\Symantec Shared\SPBBC\SPBBCSvc.exe
C:\Programmi\File comuni\Symantec Shared\ccEvtMgr.exe
C:\WINDOWS\System32\S3hotkey.exe
C:\WINDOWS\System32\S3tray2.exe
C:\Programmi\Synaptics\SynTP\SynTPLpr.exe
C:\Programmi\Synaptics\SynTP\SynTPEnh.exe
C:\Programmi\Java\j2re1.4.2_04\bin\jusched.exe
C:\Programmi\File comuni\Symantec Shared\ccApp.exe
C:\Programmi\Bluetooth Software\BTTray.exe
C:\PROGRA~1\BLUETO~1\BTSTAC~1.EXE
C:\Programmi\Bluetooth Software\bin\btwdins.exe
C:\Programmi\Norton AntiVirus\IWP\NPFMntor.exe
C:\WINDOWS\system32\slserv.exe
C:\WINDOWS\System32\svchost.exe
C:\Programmi\File comuni\Symantec Shared\CCPD-LC\symlcsvc.exe
C:\Programmi\Norton AntiVirus\navapsvc.exe
C:\Documents and Settings\IGO 2440\Desktop\HijackThis.exe

R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://www.google.it/
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Search_URL = http://rd.yahoo.com/customize/ymsgr/defaults/su/*http://www.yahoo.com
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Bar = http://rd.yahoo.com/customize/ymsgr/defaults/sb/*http://www.yahoo.com/ext/search/search.html
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Page = http://rd.yahoo.com/customize/ymsgr/defaults/sp/*http://www.yahoo.com
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Local Page =
R1 - HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings,ProxyServer = 217.200.200.53:80
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Collegamenti
O2 - BHO: AcroIEHlprObj Class - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\apps\Adobe\Acrobat 5.0\Reader\ActiveX\AcroIEHelper.ocx
O2 - BHO: CleanMyPC Popup Blocker - {7A9BC6B1-7F27-47c6-A66D-13582E81E537} - C:\Programmi\CleanMyPC Popup Blocker\CleanBHO.dll
O2 - BHO: NAV Helper - {BDF3E430-B101-42AD-A544-FADC6B084872} - C:\Programmi\Norton AntiVirus\NavShExt.dll
O3 - Toolbar: Norton AntiVirus - {42CDD1BF-3FFB-4238-8AD1-7859DF00B1D6} - C:\Programmi\Norton AntiVirus\NavShExt.dll
O3 - Toolbar: CleanMyPC Toolbar - {04164EC4-1E48-4279-818E-3721931E7636} - C:\Programmi\CleanMyPC Popup Blocker\CleanBar.dll
O3 - Toolbar: &Radio - {8E718888-423F-11D2-876E-00A0C9082467} - C:\WINDOWS\System32\msdxm.ocx
O4 - HKLM\..\Run: [S3hotkey] S3hotkey.exe
O4 - HKLM\..\Run: [S3TRAY2] S3tray2.exe
O4 - HKLM\..\Run: [SynTPLpr] C:\Programmi\Synaptics\SynTP\SynTPLpr.exe
O4 - HKLM\..\Run: [SynTPEnh] C:\Programmi\Synaptics\SynTP\SynTPEnh.exe
O4 - HKLM\..\Run: [SunJavaUpdateSched] C:\Programmi\Java\j2re1.4.2_04\bin\jusched.exe
O4 - HKLM\..\Run: [ccApp] "C:\Programmi\File comuni\Symantec Shared\ccApp.exe"
O4 - HKLM\..\Run: [SSC_UserPrompt] C:\Programmi\File comuni\Symantec Shared\Security Center\UsrPrmpt.exe
O4 - Global Startup: BTTray.lnk = ?
O8 - Extra context menu item: Invia a &Bluetooth - C:\Programmi\Bluetooth Software\btsendto_ie_ctx.htm
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\WINDOWS\System32\msjava.dll
O9 - Extra 'Tools' menuitem: Sun Java Console - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\WINDOWS\System32\msjava.dll
O9 - Extra button: @btrez.dll,-4015 - {CCA281CA-C863-46ef-9331-5C8D4460577F} - C:\Programmi\Bluetooth Software\btsendto_ie.htm
O9 - Extra 'Tools' menuitem: @btrez.dll,-4017 - {CCA281CA-C863-46ef-9331-5C8D4460577F} - C:\Programmi\Bluetooth Software\btsendto_ie.htm
O14 - IERESET.INF: START_PAGE_URL=www.packardbell.it/center
O16 - DPF: {6414512B-B978-451D-A0D8-FCFDF33E833C} (WUWebControl Class) - http://update.microsoft.com/windowsupdate/v6/V5Controls/en/x86/client/wuweb_site.cab?1121254033932
O16 - DPF: {644E432F-49D3-41A1-8DD5-E099162EEEC5} (Symantec RuFSI Utility Class) - http://security.symantec.com/sscv6/SharedContent/common/bin/cabsa.cab
O23 - Service: Bluetooth Service (btwdins) - Broadcom Corporation - C:\Programmi\Bluetooth Software\bin\btwdins.exe
O23 - Service: Symantec Event Manager (ccEvtMgr) - Symantec Corporation - C:\Programmi\File comuni\Symantec Shared\ccEvtMgr.exe
O23 - Service: Symantec Password Validation (ccPwdSvc) - Symantec Corporation - C:\Programmi\File comuni\Symantec Shared\ccPwdSvc.exe
O23 - Service: Symantec Settings Manager (ccSetMgr) - Symantec Corporation - C:\Programmi\File comuni\Symantec Shared\ccSetMgr.exe
O23 - Service: Servizio Auto-Protect di Norton AntiVirus (navapsvc) - Symantec Corporation - C:\Programmi\Norton AntiVirus\navapsvc.exe
O23 - Service: Norton AntiVirus Firewall Monitor Service (NPFMntor) - Symantec Corporation - C:\Programmi\Norton AntiVirus\IWP\NPFMntor.exe
O23 - Service: SAVScan - Symantec Corporation - C:\Programmi\Norton AntiVirus\SAVScan.exe
O23 - Service: ScriptBlocking Service (SBService) - Symantec Corporation - C:\PROGRA~1\FILECO~1\SYMANT~1\SCRIPT~1\SBServ.exe
O23 - Service: SmartLinkService (SLService) - - C:\WINDOWS\SYSTEM32\slserv.exe
O23 - Service: Symantec Network Drivers Service (SNDSrvc) - Symantec Corporation - C:\Programmi\File comuni\Symantec Shared\SNDSrvc.exe
O23 - Service: Symantec SPBBCSvc (SPBBCSvc) - Symantec Corporation - C:\Programmi\File comuni\Symantec Shared\SPBBC\SPBBCSvc.exe
O23 - Service: Symantec Core LC - Symantec Corporation - C:\Programmi\File comuni\Symantec Shared\CCPD-LC\symlcsvc.exe
O23 - Service: Gruppo di continuità (UPS) - Unknown owner - C:\WINDOWS\System32\ups.exe (file missing)

Grazie Alfonso ho fatto come mi hai detto, di virus non ne vengono rilevati sul pc ma l'unica riga che non riesco a togliere è questa:

O23 - Service: Gruppo di continuità (UPS) - Unknown owner - C:\WINDOWS\System32\ups.exe (file missing)

ho usato hijackthis sia in modalità provvisoria e normale ma quando rifaccio il log me lo da sempre come processo attivo, può essere un problema? Eventualmente esiste un modo per eliminarlo? Grazie