Hello again - I think everything seems to be functioning great! I'm no longer experiencing ad popups and my desktop is stable. I can't thank you enough!

I deleted my old restore points as you instructed and uninstalled Combofix. I then updated to Internet Explorer 7 and used the Windows Update website to download all the indicated critical updates for both Windows (including XP Service Pack 3) and Microsoft Office (Including Office 2003 Service Pack 3). I followed your instructions for adjusting the settings of Internet Explorer and made sure Windows automatic updates were on. I actually wasn't aware that updating regularly was important for security purposes, so thank you for all your tips and advice!

I just have one more question - I noticed when I ran the Kaspersky online scan that 12 infected items were identified (they are listed in the log file in my previous post). Did Kaspersky delete these files? If not, can I do so myself? Also, for regular maintenance I scan my system about once a month with CCleaner to delete old cookies and unnecessary files. Do you recommend against this, or have any suggestions other than updating regularly and keeping my antivirus and antispyware software up-to-date?

One last thing - I use Symantec Antivirus, and I don't think it runs unless I open the program (i.e., I don't think it is constantly on the lookout for threats). Is this something I can change? If so, should I?

Thank you so much again for all your help!