Decompile - Remove Trojan

I have an old game for the computer that is unfortunately infected with a trojan. I would like someone to decompile it, remove the infection, make sure it works with Windows Vista, and then give it back to me. Once you have completed the job, I will hire someone else to decompile it and go over the code, checking your work. This should be pretty simple to do for someone who's experienced enough. Now, remember, the executable is infected. But it's infection is very outdated - very very old. Originally created back in the days when we still used 5" floppy drives. I can't tell you exactly what it does as I've never installed it on the computer I'm using. But I'm sure at this point, it's pretty harmless. I'm just not sure. This is why I need you. So please use caution when downloading the attached file.