If Windows NT or Windows 2000 is configured to view thumbnail images of .jpg files, Windows Explorer may fault or hang.

This can be caused by having an improper data value in the registry. Use Regedt32 to navigate to:

HKEY_LOCAL_MACHINE\Software\Classes\.jpg

Double-click the Content value name in the right hand pane. If the string value is image/xbm, change it to image/jpeg.