I suppose you don't have high graphics set on on achat?
Deleting the files in the AChat folder you say? Well, this is, what I did:1. uninstalling AChat2. going to AppData/Local, deleting the whole AChat folder with all that was left in there3. going to the same place, finding the folder Programs, in there deleting AChat_old (or something like that)4. rebooting my computer5. downloading and installing AChat version 2.11The AppCrash still there.