I'm not sure that registry changes are needed. It sounds as if ctl3d32.dll is registered and that the original file has simply been restored after having inadvertently been replaced by a different file of the same name. (The different versions all come with the MS C++ development kit and it is easy enough for developers to confuse them since they are named the same). I worked on a project in 1997 and one of the Windows programmers managed to write code that deleted several system dlls on my PC. I simply copied the deleted dlls back into c
windows\system and haven't been bothered since.