Ho seguito tutti i vostri consigli passando il sistema con antivirus (AV) spyware, ad ware ecc. poi ho voluto provare a fare il controllo automatico del log dove mi venivano segnalati in rosso alcuni file da eliminare:

C:\PROGRAMMI\VVSN\VVSN.EXE
O4 - HKLM\..\Run: [VVSN] C:\PROGRAMMI\VVSN\VVSN.EXE

C:\WINDOWS\ptsnoop.exe
O4 - HKLM\..\Run: [PTSNOOP] ptsnoop.exe

Per i primi due non c’è stato problema e sono stati eliminati, mentre per gli altri due (ptsnoop) nonostante abbia provato con HijackThis (fix) varie volte, in modalità provvisoria, non si tolgono.

Inoltre, da una scannerizzazione con AV, mi risulta un file segnalato “Warning” che non si toglie:C:\windows\win386.swp.

Allego a questo punto il log per un vostro eventuale gentile controllo. Vi ringrazio anticipatamente per il vostro prezioso consiglio, saluti Claudio.

Logfile of HijackThis v1.99.1
Scan saved at 22.39.19, on 11/11/06
Platform: Windows 98 SE (Win9x 4.10.2222A)
MSIE: Internet Explorer v6.00 SP1 (6.00.2800.1106)

Running processes:
C:\WINDOWS\SYSTEM\KERNEL32.DLL
C:\WINDOWS\SYSTEM\MSGSRV32.EXE
C:\WINDOWS\SYSTEM\MPREXE.EXE
C:\WINDOWS\SYSTEM\MSTASK.EXE
C:\WINDOWS\SYSTEM\KB891711\KB891711.EXE
C:\WINDOWS\SYSTEM\ZONELABS\VSMON.EXE
C:\PROGRAMMI\ANTIVIR PERSONALEDITION CLASSIC\SCHEDM.EXE
C:\WINDOWS\SYSTEM\mmtask.tsk
C:\WINDOWS\EXPLORER.EXE
C:\WINDOWS\SYSTEM\RNAAPP.EXE
C:\WINDOWS\SYSTEM\TAPISRV.EXE
C:\WINDOWS\TASKMON.EXE
C:\WINDOWS\SYSTEM\SYSTRAY.EXE
C:\WINDOWS\SYSTEM\SISTRAY.EXE
C:\WINDOWS\SYSTEM\KHOOKER.EXE
C:\WINDOWS\SYSTEM\DDHELP.EXE
C:\WINDOWS\SYSTEM\STIMON.EXE
C:\WINDOWS\SYSTEM\QTTASK.EXE
C:\PROGRAMMI\VVSN\VVSN.EXE
C:\PROGRAMMI\ZONE LABS\ZONEALARM\ZLCLIENT.EXE
C:\PROGRAMMI\FILE COMUNI\REAL\UPDATE_OB\REALSCHED.EXE
C:\PROGRAMMI\ELABORATE BYTES\CLONECD\CLONECDTRAY.EXE
C:\PROGRAMMI\ANTIVIR PERSONALEDITION CLASSIC\AVGCTRL.EXE
C:\WINDOWS\ptsnoop.exe
C:\PROGRAMMI\STOPDIALERS\STOPDIALER.EXE
C:\PROGRAMMI\SAGEM\SAGEM F@ST 800-840\DSLMON.EXE
C:\WINDOWS\SYSTEM\WMIEXE.EXE
D:\PROGRAMMI\SICUREZZA\HIJACK\HIJACKTHIS.EXE

R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://digilander.iol.it/AIBESEMILIAROMAGNA
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Collegamenti
O2 - BHO: SSVHelper Class - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Programmi\Java\jre1.5.0_06\bin\ssv.dll
O2 - BHO: (no name) - {53707962-6F74-2D53-2644-206D7942484F} - C:\Programmi\Spybot - Search and Destroy\SDHelper.dll
O2 - BHO: AcroIEHlprObj Class - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\PROGRAMMI\ADOBE\ACROBAT 6.0\READER\ACTIVEX\ACROIEHELPER.DLL
O3 - Toolbar: andRadio - {8E718888-423F-11D2-876E-00A0C9082467} - C:\WINDOWS\SYSTEM\MSDXM.OCX
O3 - Toolbar: Yahoo! Toolbar con blocco Pop-Up - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - C:\PROGRAMMI\YAHOO!\COMPANION\INSTALLS\CPN\YT.DLL
O4 - HKLM\..\Run: [ScanRegistry] C:\WINDOWS\scanregw.exe /autorun
O4 - HKLM\..\Run: [TaskMonitor] C:\WINDOWS\taskmon.exe
O4 - HKLM\..\Run: [SystemTray] SysTray.Exe
O4 - HKLM\..\Run: [LoadPowerProfile] Rundll32.exe powrprof.dll,LoadCurrentPwrScheme
O4 - HKLM\..\Run: [SiS Tray] C:\WINDOWS\SYSTEM\SISTRAY.EXE
O4 - HKLM\..\Run: [SiS KHooker] C:\WINDOWS\SYSTEM\khooker.exe
O4 - HKLM\..\Run: [CountrySelection] pctptt.exe
O4 - HKLM\..\Run: [autoclk] autoclk.exe
O4 - HKLM\..\Run: [StillImageMonitor] C:\WINDOWS\SYSTEM\STIMON.EXE
O4 - HKLM\..\Run: [QuickTime Task] "C:\WINDOWS\SYSTEM\QTTASK.EXE" -atboottime
O4 - HKLM\..\Run: [VVSN] C:\PROGRAMMI\VVSN\VVSN.EXE
O4 - HKLM\..\Run: [Zone Labs Client] C:\Programmi\Zone Labs\ZoneAlarm\zlclient.exe
O4 - HKLM\..\Run: [TkBellExe] "C:\Programmi\File comuni\Real\Update_OB\realsched.exe" -osboot
O4 - HKLM\..\Run: [CloneCDTray] "C:\Programmi\Elaborate Bytes\CloneCD\CloneCDTray.exe"
O4 - HKLM\..\Run: [avgctrl] "C:\Programmi\AntiVir PersonalEdition Classic\avgctrl.exe" /min
O4 - HKLM\..\Run: [ImInstaller_IncrediMail] C:\WINDOWS\TEMP\ImInstaller\IncrediMail\IMLOADER.EXE -startup -product IncrediMail
O4 - HKLM\..\Run: [PTSNOOP] ptsnoop.exe
O4 - HKLM\..\RunServices: [LoadPowerProfile] Rundll32.exe powrprof.dll,LoadCurrentPwrScheme
O4 - HKLM\..\RunServices: [SchedulingAgent] mstask.exe
O4 - HKLM\..\RunServices: [KB891711] C:\WINDOWS\SYSTEM\KB891711\KB891711.EXE
O4 - HKLM\..\RunServices: [TrueVector] C:\WINDOWS\SYSTEM\ZONELABS\VSMON.EXE -service
O4 - HKLM\..\RunServices: [schedm] "C:\Programmi\AntiVir PersonalEdition Classic\schedm.exe"
O4 - Startup: Microsoft Office.lnk = C:\Programmi\Microsoft Office\Office\OSA9.EXE
O4 - Startup: Stop Dialers.lnk = C:\Programmi\StopDialers\StopDialer.exe
O4 - Startup: DSLMON.lnk = C:\Programmi\SAGEM\SAGEM F@st 800-840\dslmon.exe
O8 - Extra context menu item: Download with GetRight - C:\Programmi\GetRight\GRdownload.htm
O8 - Extra context menu item: Open with GetRight Browser - C:\Programmi\GetRight\GRbrowse.htm
O9 - Extra button: Related - {c95fe080-8f5d-11d2-a20b-00aa003c157a} - C:\WINDOWS\web\related.htm
O9 - Extra 'Tools' menuitem: Show andRelated Links - {c95fe080-8f5d-11d2-a20b-00aa003c157a} - C:\WINDOWS\web\related.htm
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\PROGRAMMI\JAVA\JRE1.5.0_06\BIN\SSV.DLL
O9 - Extra 'Tools' menuitem: Sun Java Console - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\PROGRAMMI\JAVA\JRE1.5.0_06\BIN\SSV.DLL
O9 - Extra button: (no name) - {85d1f590-48f4-11d9-9669-0800200c9a66} - :windir:\bdoscandel.exe (file missing)
O9 - Extra 'Tools' menuitem: Uninstall BitDefender Online Scanner v8 - {85d1f590-48f4-11d9-9669-0800200c9a66} - :windir%\bdoscandel.exe (file missing)
O12 - Plugin for .pdf: C:\PROGRA~1\INTERN~1\PLUGINS\nppdf32.dll
O16 - DPF: {150E326A-2709-467F-B384-3261EEA6CB5B} (P_e_S Control) - http://services.abbeynet.it/webclient/cab/PS-1.2.2.0_heavy.cab
O16 - DPF: {F00F4763-7355-4725-82F7-0DA94A256D46} (IncrediMail) - http://www2.incredimail.com/contents/setup/downloader/imloader.cab
O16 - DPF: {5D86DDB5-BDF9-441B-9E9E-D4730F4EE499} (BDSCANONLINE Control) - http://download.bitdefender.com/resources/scan8/oscan8.cab

grazie per l'aiuto