Il mio log è il seguente:
Logfile of HijackThis v1.99.1
Scan saved at 23.06.36, on 28/06/2006
Platform: Windows XP SP2 (WinNT 5.01.2600)
MSIE: Internet Explorer v6.00 SP2 (6.00.2900.2180)

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\Ati2evxx.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\system32\Ati2evxx.exe
C:\WINDOWS\Explorer.EXE
C:\Programmi\File comuni\Symantec Shared\ccProxy.exe
C:\Programmi\File comuni\Symantec Shared\ccSetMgr.exe
C:\Programmi\Norton Internet Security\ISSVC.exe
C:\Programmi\File comuni\Symantec Shared\SNDSrvc.exe
C:\Programmi\File comuni\Symantec Shared\SPBBC\SPBBCSvc.exe
C:\Programmi\File comuni\Symantec Shared\ccEvtMgr.exe
C:\WINDOWS\system32\spoolsv.exe
C:\Programmi\ewido anti-spyware 4.0\guard.exe
C:\Programmi\Norton Internet Security\Norton AntiVirus\navapsvc.exe
C:\WINDOWS\system32\svchost.exe
C:\Programmi\File comuni\Symantec Shared\CCPD-LC\symlcsvc.exe
C:\Programmi\ULI5289\ALi5289.exe
C:\WINDOWS\SOUNDMAN.EXE
C:\Programmi\ATI Technologies\ATI Control Panel\atiptaxx.exe
C:\Programmi\CyberLink\PowerDVD\PDVDServ.exe
C:\Programmi\LifeView TVR\Remote.exe
C:\Programmi\LifeView TVR\RecSche.exe
C:\Programmi\ZyXEL\ADSL USB Modem\CnxDslTb.exe
C:\Programmi\Java\j2re1.4.2_02\bin\jusched.exe
C:\WINDOWS\System32\spool\DRIVERS\W32X86\3\E_S4I0S2.EXE
C:\Programmi\Hercules\Audio\Hercules DJ Console\DJConsoleMixer.exe
C:\Programmi\File comuni\Symantec Shared\ccApp.exe
C:\Programmi\QuickTime\qttask.exe
C:\Programmi\Winamp\winampa.exe
C:\Programmi\ScanSoft\OmniPageSE2.0\OpwareSE2.exe
C:\Programmi\Spyware Terminator\SpywareTerminatorShield.exe
C:\Programmi\ewido anti-spyware 4.0\ewido.exe
C:\WINDOWS\system32\ctfmon.exe
C:\Programmi\Internet Explorer\iexplore.exe
C:\Programmi\File comuni\Symantec Shared\AdBlocking\NSMdtr.exe
C:\Documents and Settings\Roma\Documenti\Download\File da Installare\File Aiutamici\hijackthis\HijackThis.exe
C:\Programmi\Messenger\msmsgs.exe

R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://www.tele2internet.it/?1125893261
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Window Title = Microsoft Internet Explorer
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Collegamenti
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: RXResultTracker Class - {59879FA4-4790-461c-A1CC-4EC4DE4CA483} - C:\Programmi\RXToolBar\sfcont.dll (file missing)
O2 - BHO: Norton Internet Security - {9ECB9560-04F9-4bbc-943D-298DDF1699E1} - C:\Programmi\File comuni\Symantec Shared\AdBlocking\NISShExt.dll
O2 - BHO: NAV Helper - {BDF3E430-B101-42AD-A544-FADC6B084872} - C:\Programmi\Norton Internet Security\Norton AntiVirus\NavShExt.dll
O2 - BHO: EpsonToolBandKicker Class - {E99421FB-68DD-40F0-B4AC-B7027CAE2F1A} - C:\Programmi\EPSON\EPSON Web-To-Page\EPSON Web-To-Page.dll
O3 - Toolbar: EPSON Web-To-Page - {EE5D279F-081B-4404-994D-C6B60AAEBA6D} - C:\Programmi\EPSON\EPSON Web-To-Page\EPSON Web-To-Page.dll
O3 - Toolbar: Norton Internet Security - {0B53EAC3-8D69-4b9e-9B19-A37C9A5676A7} - C:\Programmi\File comuni\Symantec Shared\AdBlocking\NISShExt.dll
O3 - Toolbar: Norton AntiVirus - {42CDD1BF-3FFB-4238-8AD1-7859DF00B1D6} - C:\Programmi\Norton Internet Security\Norton AntiVirus\NavShExt.dll
O4 - HKLM\..\Run: [ALi5289] C:\Programmi\ULI5289\ALi5289.exe
O4 - HKLM\..\Run: [SoundMan] SOUNDMAN.EXE
O4 - HKLM\..\Run: [ATIPTA] C:\Programmi\ATI Technologies\ATI Control Panel\atiptaxx.exe
O4 - HKLM\..\Run: [RemoteControl] C:\Programmi\CyberLink\PowerDVD\PDVDServ.exe
O4 - HKLM\..\Run: [NeroFilterCheck] C:\WINDOWS\system32\NeroCheck.exe
O4 - HKLM\..\Run: [Remote] C:\Programmi\LifeView TVR\Remote.exe
O4 - HKLM\..\Run: [RecSche] "C:\Programmi\LifeView TVR\RecSche.exe"
O4 - HKLM\..\Run: [CnxDslTaskBar] "C:\Programmi\ZyXEL\ADSL USB Modem\CnxDslTb.exe"
O4 - HKLM\..\Run: [SunJavaUpdateSched] C:\Programmi\Java\j2re1.4.2_02\bin\jusched.exe
O4 - HKLM\..\Run: [EPSON Stylus C66 Series] C:\WINDOWS\System32\spool\DRIVERS\W32X86\3\E_S4I0S2.EXE /P23 "EPSON Stylus C66 Series" /O6 "USB001" /M "Stylus C66"
O4 - HKLM\..\Run: [DJ Console] C:\Programmi\Hercules\Audio\Hercules DJ Console\DJConsoleMixer.exe -hide
O4 - HKLM\..\Run: [ccApp] "C:\Programmi\File comuni\Symantec Shared\ccApp.exe"
O4 - HKLM\..\Run: [Symantec NetDriver Monitor] C:\PROGRA~1\SYMNET~1\SNDMon.exe /Consumer
O4 - HKLM\..\Run: [QuickTime Task] "C:\Programmi\QuickTime\qttask.exe" -atboottime
O4 - HKLM\..\Run: [WinampAgent] C:\Programmi\Winamp\winampa.exe
O4 - HKLM\..\Run: [OpwareSE2] "C:\Programmi\ScanSoft\OmniPageSE2.0\OpwareSE2.exe"
O4 - HKLM\..\Run: [OPSE reminder] "C:\Programmi\ScanSoft\OmniPageSE2.0\EregIta\Ereg.exe" -r "C:\Programmi\ScanSoft\OmniPageSE2.0\EregIta\ereg.ini"
O4 - HKLM\..\Run: [SpywareTerminator] "C:\Programmi\Spyware Terminator\SpywareTerminatorShield.exe"
O4 - HKLM\..\Run: [!ewido] "C:\Programmi\ewido anti-spyware 4.0\ewido.exe" /minimized
O4 - HKCU\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\ctfmon.exe
O4 - HKCU\..\Run: [MSMSGS] "C:\Programmi\Messenger\msmsgs.exe" /background
O4 - Global Startup: Avvio veloce di Adobe Reader.lnk = C:\Programmi\Adobe\Acrobat 7.0\Reader\reader_sl.exe
O4 - Global Startup: Microsoft Office.lnk = C:\Programmi\Microsoft Office\Office10\OSA.EXE
O8 - Extra context menu item: &Search - http://kn.bar.need2find.com/KN/menusearch.html?p=KN
O8 - Extra context menu item: E&sporta in Microsoft Excel - res://C:\PROGRA~1\MICROS~2\Office10\EXCEL.EXE/3000
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Programmi\Java\j2re1.4.2_02\bin\npjpi142_02.dll
O9 - Extra 'Tools' menuitem: Sun Java Console - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Programmi\Java\j2re1.4.2_02\bin\npjpi142_02.dll
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
O16 - DPF: {17492023-C23A-453E-A040-C7C580BBF700} (Windows Genuine Advantage Validation Tool) - http://go.microsoft.com/fwlink/?linkid=39204
O16 - DPF: {2BC66F54-93A8-11D3-BEB6-00105AA9B6AE} (Symantec AntiVirus scanner) - http://security.symantec.com/sscv6/SharedContent/vc/bin/AvSniff.cab
O16 - DPF: {644E432F-49D3-41A1-8DD5-E099162EEEC5} (Symantec RuFSI Utility Class) - http://security.symantec.com/sscv6/SharedContent/common/bin/cabsa.cab
O16 - DPF: {6E32070A-766D-4EE6-879C-DC1FA91D2FC3} (MUWebControl Class) - http://update.microsoft.com/microsoftupdate/v6/V5Controls/en/x86/client/muweb_site.cab?1124657234515
O18 - Filter: text/html - {2AB289AE-4B90-4281-B2AE-1F4BB034B647} - C:\Programmi\RXToolBar\sfcont.dll
O23 - Service: Ati HotKey Poller - ATI Technologies Inc. - C:\WINDOWS\system32\Ati2evxx.exe
O23 - Service: ATI Smart - Unknown owner - C:\WINDOWS\system32\ati2sgag.exe
O23 - Service: Symantec Event Manager (ccEvtMgr) - Symantec Corporation - C:\Programmi\File comuni\Symantec Shared\ccEvtMgr.exe
O23 - Service: Symantec Network Proxy (ccProxy) - Symantec Corporation - C:\Programmi\File comuni\Symantec Shared\ccProxy.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: ewido anti-spyware 4.0 guard - Anti-Malware Development a.s. - C:\Programmi\ewido anti-spyware 4.0\guard.exe
O23 - Service: ISSvc (ISSVC) - Symantec Corporation - C:\Programmi\Norton Internet Security\ISSVC.exe
O23 - Service: Servizio Auto-Protect di Norton AntiVirus (navapsvc) - Symantec Corporation - C:\Programmi\Norton Internet Security\Norton AntiVirus\navapsvc.exe
O23 - Service: SAVScan - Symantec Corporation - C:\Programmi\Norton Internet Security\Norton AntiVirus\SAVScan.exe
O23 - Service: ScriptBlocking Service (SBService) - Symantec Corporation - C:\PROGRA~1\FILECO~1\SYMANT~1\SCRIPT~1\SBServ.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

Nel pannello installazioni applicazioni non c'è RXToolbar. Chiedevo prima di effettuare quanto mi hai suggerivo, che il mio PC non presenta nessun problema di funzionamento o rallentamenti, quali sono i rischi se il problema evidenziato non viene risolto?

Ho eseguito quanto mi hai comunicato. Tutto ok.