Nitrous Brakes Car

[yubetcha1]

I can't figure this out. I played the game a few years ago and everything was working perfectly. I started to run out of disk space so I uninstalled it. Yesterday I reinstalled it and loaded it. I am speeding along as fast as I can. I hit the nitrous (using a PC) . The flames come out the back, but the car actually brakes. It slows down very fast and everyone passes me. It is as if I hit the brakes very hard. Help. I checked the game settings but nothing helps.