Converting 16-bit DOS .com assembly for use on 64-bit

Question

I wrote few programs in assembly in flat assembler for 32bit windows xp. But now that I have 64bit windows 8 I can\'t run the .com files, as they appear to be incompatible with

Answer 1

A .com file is 16-bit. You can use 32-bit instructions and registers, but it's 16-bit code. A 64-bit CPU, once it's put in "long mode", does not support vm86 which is what XP uses to run .com files. Blame AMD, not MS (this time). Use an emulator (DosBox, etc.) or convert your code to 32-bit (which should run on a 64-bit OS)