Susan- How old is your computer? If it is a fairly new one, disregard, but if it is an older one with a fairly small video graphics card you may be running into problems in that area.
Playing around with UFT wallpaper or making other changes in graphics might trigger a "memory" problem, which can vary with version number. Newer is better, both for UFT and the computer. Other memory problems would seem unlikely, but I don't remember all the Error # designations, even after looking in Help in UFT 3.0.
It might reqire a UFT reinstallation, even with XP. I ended up doing that after some Display experiment or other fairly recently. Be certain of your backup, though. John