appcompat error (I Moved this to Tech Q & A

I have run across this error on several machines. I get a message that an app has caused an error and has to close. It wants to send the following file C:\DOCUME~1\username\LOCALS!1\Temp\WER2.tmp.dir00\accompat.txt. On three of these machines it kept the app from working at all. I finally had to reformat the PC to get all the apps to work correctly.

How can I find out what is causing this and how to fix it without reformatting? Thanks ahead of time for your help.