I have had a problem with my browser shutting down on several sites (for instance: http://www.colostate.edu/Depts/Econ/). It happens to both IE6 and Mozilla Firefox. My OS is WinXP. I have used AdAware and other programs (SpySweeper and CWShredder). I still have the problem and have now run a Hijack This log for you to examine. Thanks so much in advance for your help...

Logfile of HijackThis v1.99.0
Scan saved at 10:22:14 AM, on 12/17/2004
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\svchost.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\system32\spoolsv.exe
C:\PROGRA~1\VCOM\Fix-It\mxtask.exe
C:\Program Files\Network Associates\Common Framework\FrameworkService.exe
C:\Program Files\Network Associates\VirusScan\mcshield.exe
C:\Program Files\Network Associates\VirusScan\vstskmgr.exe
C:\PROGRA~1\McAfee.com\PERSON~1\MPFSERVICE.exe
C:\PROGRA~1\McAfee.com\PERSON~1\Mp***ent.exe
C:\WINDOWS\Explorer.EXE
C:\PROGRA~1\VCOM\Fix-It\mxtask.exe
C:\Program Files\Synaptics\SynTP\SynTPLpr.exe
C:\PROGRA~1\McAfee.com\PERSON~1\MpfTray.exe
C:\Program Files\Network Associates\VirusScan\SHSTAT.EXE
C:\Program Files\Network Associates\Common Framework\UpdaterUI.exe
C:\Program Files\Common Files\Network Associates\TalkBack\tbmon.exe
C:\Program Files\Synaptics\SynTP\SynTPEnh.exe
C:\Program Files\Adobe\Acrobat 6.0\Distillr\acrotray.exe
C:\Program Files\Novell\GroupWise\Notify.exe
C:\Program Files\Novell\GroupWise\GrpWise.exe
C:\Program Files\Mozilla Firefox\firefox.exe
C:\Documents and Settings\Vacita.VACILTHP\Desktop\HijackThis.exe

R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Local Page =
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Local Page =
O2 - BHO: AcroIEHlprObj Class - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Adobe\Acrobat 6.0\Acrobat\ActiveX\AcroIEHelper.dll
O2 - BHO: Google Toolbar Helper - {AA58ED58-01DD-4d91-8333-CF10577473F7} - c:\program files\google\googletoolbar2.dll
O2 - BHO: AcroIEToolbarHelper Class - {AE7CD045-E861-484f-8273-0445EE161910} - C:\Program Files\Adobe\Acrobat 6.0\Acrobat\AcroIEFavClient.dll
O3 - Toolbar: Adobe PDF - {47833539-D0C5-4125-9FA8-0819E2EAAC93} - C:\Program Files\Adobe\Acrobat 6.0\Acrobat\AcroIEFavClient.dll
O3 - Toolbar: &Google - {2318C2B1-4965-11d4-9B18-009027A5CD4F} - c:\program files\google\googletoolbar2.dll
O3 - Toolbar: Search Bar - {0A8CE102-FA03-4612-9BEE-7FE5452F4CB1} - C:\WINDOWS\system32\srchbar.dll
O4 - HKLM\..\Run: [SynTPLpr] C:\Program Files\Synaptics\SynTP\SynTPLpr.exe
O4 - HKLM\..\Run: [MPFExe] C:\PROGRA~1\McAfee.com\PERSON~1\MpfTray.exe
O4 - HKLM\..\Run: [ShStatEXE] "C:\Program Files\Network Associates\VirusScan\SHSTAT.EXE" /STANDALONE
O4 - HKLM\..\Run: [McAfeeUpdaterUI] "C:\Program Files\Network Associates\Common Framework\UpdaterUI.exe" /StartedFromRunKey
O4 - HKLM\..\Run: [Network Associates Error Reporting Service] "C:\Program Files\Common Files\Network Associates\TalkBack\tbmon.exe"
O4 - HKLM\..\Run: [NeroFilterCheck] C:\WINDOWS\system32\NeroCheck.exe
O4 - HKLM\..\Run: [SynTPEnh] C:\Program Files\Synaptics\SynTP\SynTPEnh.exe
O4 - Global Startup: Acrobat Assistant.lnk = C:\Program Files\Adobe\Acrobat 6.0\Distillr\acrotray.exe
O4 - Global Startup: GroupWise Notify.lnk = C:\Program Files\Novell\GroupWise\Notify.exe
O8 - Extra context menu item: &Google Search - res://c:\program files\google\GoogleToolbar2.dll/cmsearch.html
O8 - Extra context menu item: Backward Links - res://c:\program files\google\GoogleToolbar2.dll/cmbacklinks.html
O8 - Extra context menu item: Cached Snapshot of Page - res://c:\program files\google\GoogleToolbar2.dll/cmcache.html
O8 - Extra context menu item: Similar Pages - res://c:\program files\google\GoogleToolbar2.dll/cmsimilar.html
O8 - Extra context menu item: Translate into English - res://c:\program files\google\GoogleToolbar2.dll/cmtrans.html
O9 - Extra button: Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\msmsgs.exe
O9 - Extra 'Tools' menuitem: Windows Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\msmsgs.exe
O17 - HKLM\System\CCS\Services\Tcpip\..\{5FF04C13-F018-44B8-8B09-80F5947A1C05}: NameServer = 128.8.74.2
O23 - Service: Fix-It Task Manager - V Communications, Inc. - C:\PROGRA~1\VCOM\Fix-It\mxtask.exe
O23 - Service: HP WMI Interface - Hewlett-Packard Development Company, L.P. - C:\Program Files\HPQ\SHARED\HPQWMI.exe
O23 - Service: McAfee Framework Service - Network Associates, Inc. - C:\Program Files\Network Associates\Common Framework\FrameworkService.exe
O23 - Service: Network Associates McShield - Network Associates, Inc. - C:\Program Files\Network Associates\VirusScan\mcshield.exe
O23 - Service: Network Associates Task Manager - Network Associates, Inc. - C:\Program Files\Network Associates\VirusScan\vstskmgr.exe
O23 - Service: McAfee Personal Firewall Service - McAfee Corporation - C:\PROGRA~1\McAfee.com\PERSON~1\MPFSERVICE.exe

Close all browser windows, restart Hijack This and put a checkmark next to the following entries:

R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Local Page =
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Local Page =
O3 - Toolbar: Search Bar - {0A8CE102-FA03-4612-9BEE-7FE5452F4CB1} - C:\WINDOWS\system32\srchbar.dll

Click Fix Checked

Reboot and post a fresh log

Thank you very much for your prompt reply.
I did what you just told, reboot and here is a fresh log (the problem is still there, though):

Logfile of HijackThis v1.99.0
Scan saved at 12:16:31 PM, on 12/17/2004
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\svchost.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\system32\spoolsv.exe
C:\PROGRA~1\VCOM\Fix-It\mxtask.exe
C:\Program Files\Network Associates\Common Framework\FrameworkService.exe
C:\Program Files\Network Associates\VirusScan\mcshield.exe
C:\Program Files\Network Associates\VirusScan\vstskmgr.exe
C:\PROGRA~1\McAfee.com\PERSON~1\MPFSERVICE.exe
C:\WINDOWS\Explorer.EXE
C:\PROGRA~1\McAfee.com\PERSON~1\Mp***ent.exe
C:\PROGRA~1\VCOM\Fix-It\mxtask.exe
C:\Program Files\Synaptics\SynTP\SynTPLpr.exe
C:\PROGRA~1\McAfee.com\PERSON~1\MpfTray.exe
C:\Program Files\Network Associates\VirusScan\SHSTAT.EXE
C:\Program Files\Network Associates\Common Framework\UpdaterUI.exe
C:\Program Files\Common Files\Network Associates\TalkBack\tbmon.exe
C:\Program Files\Synaptics\SynTP\SynTPEnh.exe
C:\Program Files\Adobe\Acrobat 6.0\Distillr\acrotray.exe
C:\Program Files\Novell\GroupWise\Notify.exe
C:\WINDOWS\system32\wuauclt.exe
C:\PROGRA~1\MOZILL~1\FIREFOX.EXE
C:\Documents and Settings\Vacita.VACILTHP\Desktop\HijackThis.exe

O2 - BHO: AcroIEHlprObj Class - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Adobe\Acrobat 6.0\Acrobat\ActiveX\AcroIEHelper.dll
O2 - BHO: Google Toolbar Helper - {AA58ED58-01DD-4d91-8333-CF10577473F7} - c:\program files\google\googletoolbar2.dll
O2 - BHO: AcroIEToolbarHelper Class - {AE7CD045-E861-484f-8273-0445EE161910} - C:\Program Files\Adobe\Acrobat 6.0\Acrobat\AcroIEFavClient.dll
O3 - Toolbar: Adobe PDF - {47833539-D0C5-4125-9FA8-0819E2EAAC93} - C:\Program Files\Adobe\Acrobat 6.0\Acrobat\AcroIEFavClient.dll
O3 - Toolbar: &Google - {2318C2B1-4965-11d4-9B18-009027A5CD4F} - c:\program files\google\googletoolbar2.dll
O4 - HKLM\..\Run: [SynTPLpr] C:\Program Files\Synaptics\SynTP\SynTPLpr.exe
O4 - HKLM\..\Run: [MPFExe] C:\PROGRA~1\McAfee.com\PERSON~1\MpfTray.exe
O4 - HKLM\..\Run: [ShStatEXE] "C:\Program Files\Network Associates\VirusScan\SHSTAT.EXE" /STANDALONE
O4 - HKLM\..\Run: [McAfeeUpdaterUI] "C:\Program Files\Network Associates\Common Framework\UpdaterUI.exe" /StartedFromRunKey
O4 - HKLM\..\Run: [Network Associates Error Reporting Service] "C:\Program Files\Common Files\Network Associates\TalkBack\tbmon.exe"
O4 - HKLM\..\Run: [NeroFilterCheck] C:\WINDOWS\system32\NeroCheck.exe
O4 - HKLM\..\Run: [SynTPEnh] C:\Program Files\Synaptics\SynTP\SynTPEnh.exe
O4 - Global Startup: Acrobat Assistant.lnk = C:\Program Files\Adobe\Acrobat 6.0\Distillr\acrotray.exe
O4 - Global Startup: GroupWise Notify.lnk = C:\Program Files\Novell\GroupWise\Notify.exe
O8 - Extra context menu item: &Google Search - res://c:\program files\google\GoogleToolbar2.dll/cmsearch.html
O8 - Extra context menu item: Backward Links - res://c:\program files\google\GoogleToolbar2.dll/cmbacklinks.html
O8 - Extra context menu item: Cached Snapshot of Page - res://c:\program files\google\GoogleToolbar2.dll/cmcache.html
O8 - Extra context menu item: Similar Pages - res://c:\program files\google\GoogleToolbar2.dll/cmsimilar.html
O8 - Extra context menu item: Translate into English - res://c:\program files\google\GoogleToolbar2.dll/cmtrans.html
O9 - Extra button: Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\msmsgs.exe
O9 - Extra 'Tools' menuitem: Windows Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\msmsgs.exe
O17 - HKLM\System\CCS\Services\Tcpip\..\{5FF04C13-F018-44B8-8B09-80F5947A1C05}: NameServer = 128.8.74.2
O23 - Service: Fix-It Task Manager - V Communications, Inc. - C:\PROGRA~1\VCOM\Fix-It\mxtask.exe
O23 - Service: HP WMI Interface - Hewlett-Packard Development Company, L.P. - C:\Program Files\HPQ\SHARED\HPQWMI.exe
O23 - Service: McAfee Framework Service - Network Associates, Inc. - C:\Program Files\Network Associates\Common Framework\FrameworkService.exe
O23 - Service: Network Associates McShield - Network Associates, Inc. - C:\Program Files\Network Associates\VirusScan\mcshield.exe
O23 - Service: Network Associates Task Manager - Network Associates, Inc. - C:\Program Files\Network Associates\VirusScan\vstskmgr.exe
O23 - Service: McAfee Personal Firewall Service - McAfee Corporation - C:\PROGRA~1\McAfee.com\PERSON~1\MPFSERVICE.exe

Thats a clean log. Have you installed the latest version of Java from www.java.com?

Thanks so much. Yes, that was the problem. I had an old version of Java, everything works fine now. Thank you very much!!!