I have spent about 7 hours on this, to no avail. Explorer.exe is using all CPU. Running XP HE SP 2. Running up-to-date NSW and auto updates from Windows.
Tried ending explorer in Task Manager, and restaring from Run. Tried a System Restore. Could only get back a few days. Ran Windows Defender, Ad-aware, NSW scan, Registry Mechanic. Eliminated a few nastys from msconfig/startup like nwiz.exe, ctfmon.exe. Turned off bcmwltry.exe, removecpl.exe also. Saw postings related to .avi files, made a few registry key deletes based on those. One at a time, none of these has stopped the 99%.
Now redoing all scans (NSW, Defender, Registry Mechanic, Ad-aware) from SAFE Mode.
There must be something I am not catching.