Error message: explorer.exe

Archived from groups: microsoft.public.windowsxp.general (More info?)

I have a laptop computer that has The Sims 2 and the Sims Bodyshop installed
on it. If you're not familiar with the program, the Sims Bodyshop allows you
to create skins for The Sims 2 game. My problem is whenever I extract the
files necessary to create skins to my desktop, when I try to open them in
order to alter them I get the following error message:
AppName: explorer.exe
AppVer: 6.0.2900.2180
ModName: ntdll.dll
ModVer: 5.1.2600.2180
When I first began using the program, it didn't always do this and would let
me open a few files but now it does this with every file I try to open in
C:\Documents and Settings\Mallory\My Documents\EA Games\The Sims 2\Projects.
Also, it used to tell me that my "memory cannot be read" but it doesn't give
me that message anymore. (Just in case that has anything to do with it.)
I loaded the program and game onto another computer and the program appears
to be working perfectly on that one.
Can anyone please tell me what the problem might be and if/how I can fix it?