Someone I used to work for emailed me out of the blue and said they want me to update a VB3 (!!!) program I wrote for them because customers are reporting having problems running it under Windows 7. They have lost the source code (natch). Is there a decompiler for VB3?
Unlike the later versions which used native code and are generally not reliably decompilable, VB3 (and, I think, VB4) could be usually decompiled to almost original code. The keywords you need to search for are "DoDi VB3 decompiler" or "vb3dis". Here's a page that seems to have a copy.