I think the programs that have 16-bit code are the ones that wont work in 64-bit OS, without doing some messing around. I havent had a problem with any "newer" programs and I have Vista 64. I've found that 32-bit apps install in a "Program Files (x86)" folder while the 64-bit apps install in the regular "Program Files" folder, in 64 bit Vista anyway. If the programs your looking for are rather old then theres a good chance that they and even their updates will have 16-bit code in them and not work in a 64-bit OS.