Esegui 
E' diventato lento all'avvio e sempre piu' spesso (adesso almeno una volta al giorno) si blocca totalmente e si riavvia solo dopo che ho tolto l'alimentazione, in quanto non accetta piu' comandi.
Spybot mi evidenzia, ad ogni scansione, la presenza di sfonditalia che come ho gia' visto sul forum, e' un problema per parecchi utenti.
Non sono molto pratico del pc, ma mi sono reso conto che per ottenere una soluzione devo inviarVi alcuni elementi di analisi; per cui Vi allego log di Spybot e log di Hijackthis.
Se ritenete di darmi soluzioni, chiedo che mi venga fatto un dettaglio delle operazioni da fare poiche',come detto, non sono molto pratico.
Log di Spybot :
NumbSoft: Impostazioni di avvio automatico (NVIEW) (Valore di registro, nothing done)
HKEY_USERS\S-1-5-21-3976966760-4207940353-2433079057-1003\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\NVIEW
Sfonditalia: Impostazioni (Modifica al registro, nothing done)
HKEY_USERS\S-1-5-21-3976966760-4207940353-2433079057-1003\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap\Domains\skymasters.biz\www\*!=W=4
Sfonditalia: Impostazioni (Modifica al registro, nothing done)
HKEY_USERS\S-1-5-21-3976966760-4207940353-2433079057-1003\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap\Domains\redfunny.com\www\*!=W=4
Sfonditalia: Impostazioni (Modifica al registro, nothing done)
HKEY_USERS\S-1-5-21-3976966760-4207940353-2433079057-1003\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap\Domains\archiviosex.net\www\*!=W=4
Log di Hijackthis :
Logfile of HijackThis v1.99.1
Scan saved at 17.46.25, on 17/02/2007
Platform: Windows XP SP2 (WinNT 5.01.2600)
MSIE: Internet Explorer v7.00 (7.00.6000.16414)
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:\Programmi\Windows Defender\MsMpEng.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\Explorer.EXE
C:\WINDOWS\system32\spoolsv.exe
C:\Programmi\Alwil Software\Avast4\aswUpdSv.exe
C:\Programmi\Alwil Software\Avast4\ashServ.exe
C:\Programmi\File comuni\Microsoft Shared\VS7Debug\mdm.exe
C:\WINDOWS\System32\nvsvc32.exe
C:\windows\system\hpsysdrv.exe
C:\Programmi\USB Storage RW\shwicon.exe
C:\HP\KBD\KBD.EXE
C:\Programmi\VERITAS Software\Update Manager\sgtray.exe
C:\WINDOWS\System32\spool\drivers\w32x86\3\hpztsb08.exe
C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
C:\Programmi\iTunes\iTunesHelper.exe
C:\Programmi\Windows Defender\MSASCui.exe
C:\WINDOWS\system32\ctfmon.exe
C:\WINDOWS\system32\rundll32.exe
C:\Programmi\Alwil Software\Avast4\ashMaiSv.exe
C:\Programmi\iPod\bin\iPodService.exe
C:\Programmi\Alwil Software\Avast4\ashWebSv.exe
C:\WINDOWS\system32\wuauclt.exe
C:\Onofrio\Antivirus\hijackthis\HijackThis.exe
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Bar = http://g.msn.it/0SEITIT/SAOS01?FORM=TOOLBR
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Page = http://g.msn.it/0SEITIT/SAOS01?FORM=TOOLBR
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://www.google.it/
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://go.microsoft.com/fwlink/?LinkId=69157
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Search_URL = http://go.microsoft.com/fwlink/?LinkId=54896
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Page = http://go.microsoft.com/fwlink/?LinkId=54896
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Start Page = http://go.microsoft.com/fwlink/?LinkId=69157
R1 - HKCU\Software\Microsoft\Internet Explorer\SearchURL,(Default) = http://g.msn.it/0SEITIT/SAOS01?FORM=TOOLBR
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Collegamenti
O2 - BHO: Yahoo! Companion BHO - {02478D38-C3F9-4efb-9B51-7695ECA05670} - C:\Programmi\Yahoo!\Companion\Installs\cpn\ycomp5_5_7_0.dll
O2 - BHO: Adobe PDF Reader Link Helper - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Programmi\Adobe\Acrobat 7.0\ActiveX\AcroIEHelper.dll
O2 - BHO: (no name) - {53707962-6F74-2D53-2644-206D7942484F} - C:\PROGRA~1\SPYBOT~1\SDHelper.dll
O2 - BHO: Windows Live Toolbar Helper - {BDBD1DAD-C946-4A17-ADC1-64B5B4FF55D0} - C:\Programmi\Windows Live Toolbar\msntb.dll
O3 - Toolbar: Yahoo! Companion - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - C:\Programmi\Yahoo!\Companion\Installs\cpn\ycomp5_5_7_0.dll
O3 - Toolbar: Windows Live Toolbar - {BDAD1DAD-C946-4A17-ADC1-64B5B4FF55D0} - C:\Programmi\Windows Live Toolbar\msntb.dll
O4 - HKLM\..\Run: [hpsysdrv] c:\windows\system\hpsysdrv.exe
O4 - HKLM\..\Run: [HotKeysCmds] C:\WINDOWS\System32\hkcmd.exe
O4 - HKLM\..\Run: [KYE_Showicon] "C:\Programmi\USB Storage RW\shwicon.exe" -t"KYE\USB Storage RW"
O4 - HKLM\..\Run: [KBD] C:\HP\KBD\KBD.EXE
O4 - HKLM\..\Run: [StorageGuard] "C:\Programmi\VERITAS Software\Update Manager\sgtray.exe" /r
O4 - HKLM\..\Run: [Recguard] C:\WINDOWS\SMINST\RECGUARD.EXE
O4 - HKLM\..\Run: [nwiz] nwiz.exe /installquiet /keeploaded
O4 - HKLM\..\Run: [PS2] C:\WINDOWS\system32\ps2.exe
O4 - HKLM\..\Run: [HPDJ Taskbar Utility] C:\WINDOWS\System32\spool\drivers\w32x86\3\hpztsb08.exe
O4 - HKLM\..\Run: [avast!] C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
O4 - HKLM\..\Run: [UserFaultCheck] %systemroot%\system32\dumprep 0 -u
O4 - HKLM\..\Run: [iTunesHelper] "C:\Programmi\iTunes\iTunesHelper.exe"
O4 - HKLM\..\Run: [Windows Defender] "C:\Programmi\Windows Defender\MSASCui.exe" -hide
O4 - HKCU\..\Run: [ctfmon.exe] C:\WINDOWS\system32\ctfmon.exe
O4 - HKCU\..\Run: [updateMgr] "C:\Programmi\Adobe\Acrobat 7.0\Reader\AdobeUpdateManager.exe" AcRdB7_0_8 -reboot 1
O4 - HKCU\..\Run: [NVIEW] rundll32.exe nview.dll,nViewLoadHook
O8 - Extra context menu item: Add to Windows &Live Favorites - http://favorites.live.com/quickadd.aspx
O8 - Extra context menu item: E&sporta in Microsoft Excel - res://C:\PROGRA~1\MICROS~2\OFFICE11\EXCEL.EXE/3000
O9 - Extra button: Ricerche - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - C:\PROGRA~1\MICROS~2\OFFICE11\REFIEBAR.DLL
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:\Programmi\Messenger\msmsgs.exe
O9 - Extra 'Tools' menuitem: Windows Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Programmi\Messenger\msmsgs.exe
O11 - Options group: [INTERNATIONAL] International*
O16 - DPF: {17492023-C23A-453E-A040-C7C580BBF700} (Windows Genuine Advantage Validation Tool) - http://go.microsoft.com/fwlink/?linkid=39204
O16 - DPF: {4F1E5B1A-2A80-42CA-8532-2D05CB959537} (MSN Photo Upload Tool) - http://by15fd.bay15.hotmail.msn.com/res ... nPUpld.cab
O16 - DPF: {B38870E4-7ECB-40DA-8C6A-595F0A5519FF} (MsnMessengerSetupDownloadControl Class) - http://messenger.msn.com/download/MsnMe ... loader.cab
O18 - Protocol: msnim - {828030A1-22C1-4009-854F-8E305202313F} - "C:\PROGRA~1\MSNMES~1\msgrapp.dll" (file missing)
O20 - Winlogon Notify: igfxcui - C:\WINDOWS\SYSTEM32\igfxsrvc.dll
O20 - Winlogon Notify: WgaLogon - C:\WINDOWS\SYSTEM32\WgaLogon.dll
O23 - Service: avast! iAVS4 Control Service (aswUpdSv) - Unknown owner - C:\Programmi\Alwil Software\Avast4\aswUpdSv.exe
O23 - Service: avast! Antivirus - Unknown owner - C:\Programmi\Alwil Software\Avast4\ashServ.exe
O23 - Service: avast! Mail Scanner - Unknown owner - C:\Programmi\Alwil Software\Avast4\ashMaiSv.exe" /service (file missing)
O23 - Service: avast! Web Scanner - Unknown owner - C:\Programmi\Alwil Software\Avast4\ashWebSv.exe" /service (file missing)
O23 - Service: InstallDriver Table Manager (IDriverT) - Macrovision Corporation - C:\Programmi\File comuni\InstallShield\Driver\11\Intel 32\IDriverT.exe
O23 - Service: iPodService - Apple Computer, Inc. - C:\Programmi\iPod\bin\iPodService.exe
O23 - Service: NVIDIA Driver Helper Service (NVSvc) - NVIDIA Corporation - C:\WINDOWS\System32\nvsvc32.exe
