i bought rainbow six vegas recently and installed it
the game works perfectly until i press a key on my keyboard
so during a mission, when i spawn, i can look around, shoot and do anything with the mouse, but when i press the w key to go forward, my pc freezes.
any idea why this is happening?

my PC:
Core 2 Quad
Nvidia GeForce 9800GTX+ 512mb
3.25GB RAM
Windows XP service pcak 2
Sound Card : Realtek HD audio

I take it you're using a USB Keyboard? If yes, are you using a USB hub to connect it? If yes, try connecting it directly.

Are you able to try a different keyboard just to check if the keyboard itself is the issue?

Try reinstalling your game.

You should expect more silly things like this to occur with this "wonderful" game.