I got this game and my windows xp isnt quite compatible, so maybe i sound stupid, but is it possible to upgrade from 3.00 ghz to 3.50 ghz?

Boosting your CPU speed won't make your computer more compatible. It would only reduce lag or slowdown by processing the game faster. And you shouldn't really overclock your system unless you really know what you're doing, because the excess heat produced could ruin your computer.

What exactly appears to be the compatibility issue? Does the game run at all, slow or fast? Does it crash? Or will it simply not play at all?

ok when i go to the reqirements tool it says my computer is 3 GHz and it needs to be 3.5. it does run some, but jumps from frame to frame, and sometimes when i try to open it it will close itself just before i get to the main menu. also it sometimes freezes during little cutscenes like when i rappel, and it sometimes freezes when grenades explode.

Are you sure that's what it's saying for this game? I had a look on Gamespot and found this:

quote GameSpot

Release Date: Apr 04, 2000 (US)

Minimum System Requirements
System: PII 266 or equivalent
RAM: 32 MB
Video Memory: 2 MB

Uh, yeah. well, thanks anyway.

I looked at the requirements tool again and its for R6 vegas. the shortcut to it just said "requirements tool" with a little r6 icon by it so i assumed it was for urban ops. i dont really want to drop a hundred $$ on a vid card so i guess ill live with it... thanks!