I know this is a really old thread, however I am running into the same issue and would like to know if anyone came up with a solution for the issue.
I know for a fact that MiniCAD 7 runs in Windows XP. I have ran it in Windows XP for the last few years at my school in the lab. I started to create my new image for the next school year, and before installing the software I ran all windows updates. Once that was complete I started installing Applications. After that I started testing them and found that MiniCAD would no longer run, giving me the same error as above.
So I took a computer that had last years image on it (Windows XP SP2), but didn't have MiniCAD installed, and it loaded, and launched perfectly fine. So I guess it looks as though there is a conflict with some of the Windows Updates that have came out in the last year that is causing MiniCAD to no longer run.
Does anyone have any ideas other then upgrading to Vectorworks 12? That simply will not happen. The teacher that teaches this program only uses MiniCAD 7 because he knows it. If he has to learn something new he will have to learn AutoCAD because, AutoCAD is Ministry Licensed, and we will not have to pay for it, where upgrading to a new version of Vectorworks will cost quite a bit.
Thanks for your time.