Microsoft VisualC++Runtime Library problem!!

The system is <a href="http://www.serverlogic3.com/lm/rtl3.asp?si=1&k=windows%20xp%20professional" onmouseover="window.status='Windows XP Professional'; return true;" onmouseout="window.status=''; return true;">Windows XP Professional</a> SP2, <a href="http://www.serverlogic3.com/lm/rtl3.asp?si=1&k=pentium%20iii" onmouseover="window.status='Pentium III'; return true;" onmouseout="window.status=''; return true;">Pentium III</a> Processor, an ignorant old fart operator, a perverted son, who can't stay off the "dating" and girlie sites, when off work and a grandson who occassionally gets off the games to do his school work. In July it was gone through for a virus and a good cleanup. In August, SP 2 update added along with any suggested by them. The added Popup Blocker is annoying but, occassionally beneficial. The computer seemed to be slowing down, so it was suggested that I defrag it and clean out unneeded files. I think I must have "cleaned" a little too much. These popups: "Microsoft VisualC++Runtime Library" boxes with "Runtime Error!", "Program: C:\ProgramFiles\InternetExplorer\iexplorer.exe", "abnormal proram termination". ANY ideas would be greatly appreciated. Thanx.....