JC, Not sure on directx I think you might have problems with versions later than 7.x but I might be thinking of W95. I'm pretty sure Agent Smith was right about the A and B versions though; I think if that's the case you may need to start with the B version inorder for the updates to work properly with C4D. Something else: If the program runs(for example) MFC42.dll you might have the wrong version of the dll. That happened to me with TC 4.0 it took me years to get that one straightened out. I got a similar error to yours until I got a copy of the version that the program expected to see and put it in the directory TC 4.0 was in (not in windowssystem directory - that would mess you up for sure.) - TJ