I'm running the game on win7 64bit system without any problems, so that is not the issue. Since you call it Brigade 7.62, do you have the German version of the game? If you do you might wanna check out this site, you might find s fix for your problem there:
Taktikzone
If you're using the English version it must be another issue, maybe your UAC is turned on, of maybe a anti-virus prog blocking it.
If you get it running, don't forget to install the unofficial patch before you start playing, there's an English patch in this forum, but if you need the Germn version let me know and I'll post a link to that as well.