When changing from one user to the other, the desktop
loses its icons and freezes on a blank desktop (scenic
background can be seen). Then toolbar on bottom and the
icons blink on and off.

Both users have administrator rights, and are secured
with passwords (removing the passwords makes no
difference).

System info:
Manufacturer: Dell
Model: Dimension 8200
Operating System: Microsoft Windows XP Professional
Processor: 1993 Mhz
Total Memory: 512 MB
Disk Drive: 37.3 GB

Any ideas?