I tried installing my original copy the other day. It installed like champ even after 15 years but would not run. I think a windows update to Windows 7 prevented some older games from working. I uninstalled that update and want to try to install the game again to see if that was it. Either way I'm glad it made its way to GOG though that does seem to be pretty pricey. Awesome game though so its definitely worth it if you don't own it or haven't' played it. Seems like its only natural now for Vietcong to be around the corner though it works still on Windows 7. One day and its already happening these older games probably won't run at all on new machines so I'm thankful GOG is acquiring them!
Try installing on a different drive than your OS, or at least not under the "Programs" directory, if you didn't do that already. You may have already tried running as admin and experimented with compatibility modes, but sometimes those things can help.