An Unhandled Win32 exception Occurred in explorer.exe [xxxx]

Friends,

My Windows Xp Pro PC fails with “An Unhandled Win32 exception Occurred in explorer.exe [xxxx]” or “An Unhandled Win32 Exception Occurred in iexplore.exe [xxxx]” when I start either IE7 or he Windows Explorer. I’ve completed a non-destructive reinstall of Windows and used registry cleaners/fixers, but no help. The PIDs are always either IE7 or Windows Explorer when either are started, however some other apps seem to fail as well.
Suggestions?

Thanks, Roger