Open Task Manager,
find and click "New Task..." button, then type
Taskbar and Icons missing:
(Original Message, and Response Number 1 looks like a fix?)
Also try this:
(That one is a special Posting someone made of how he fixed it.)
Another fix is un-quarintene explorer in Spydoctor.
This page has alot of XP fixes
Some require the download of a VBS, or Regedits file.
So, read at the top of that page--
"To use the Regedits" or "To use the VBS files"
Then go to line 195, then click item in right hand column.