Fatal Error : Warning Couldn't Open Ns.wad

Helpplz

As title sez when i start up the game and try go on to a server it crashes and sez that message. Neone gimme a hand plz?

I running windows XP and have uber pc that could handle this game easily.

Ty

Helpplz

<!--emo&::asrifle::--><img src='http://www.unknownworlds.com/forums/html//emoticons/asrifle.gif' border='0' style='vertical-align:middle' alt='asrifle.gif' /><!--endemo--> im running Steam

Thansal

try wording your posts in english.

and reinstall ns.