title: Why do some programs compiled for x86 do not run under x64, while some do
body: <p>I have seen that some programs which were written by me and assembled for x86 using ml.exe run fine on my Win 7 x64. I believe this is because of Wow technology.</p>
  
  <p>However, there are some programs (not written by me) which don't run. They give the error that:
  <strong>The version of this file is not compatible with the version of Windows you're running. Check you computer system infromation to see whether you need an x86 (32-bit) or x64 (64-bit) version of the program, and then contact the software publisher</strong></p>
  
  <p>Is there any way I can modify the EXE of these programs to make it run on Win 7 x64. What is the fundamental difference in these programs which make it different from other programs which run transparently.</p>