IIS and .exe problem

Hi All,
I've created some .exe applications and put them in the cgi-bin of my Windows 2003 server. It had always worked until just recently when my computer got some updated downloaded and a restart happened. Now I can't seem to get the .exes to work. I've tried putting some htm files in the cgi-bin directory and they work fine, the .exes come up "You are not authorized to view this page" (401 error). I've tried a number of things to try and resolve this problem but with no success. Any help would be greatly appreciated.

Rob