See
http://support.microsoft.com/kb/918165 "Problems in Windows
Explorer or the Windows shell after you install security update
MS06-015".
If you aren't comfortable with editing the Windows registry
yourself, then go to
http://www.kellys-korner-xp.com/xp_tweaks.htm and scroll
down to Item No. 383 "Hewlett-Packard's Share-to-Web software -
Fix". Download and run the script to automatically modify your
registry as described in KB918165. You may need to temporarily
disable your antivirus program in order to run the script.
It is anticipated that Microsoft will release a revised version
of the MS06-015 update on Tuesday, April 25.