Two Processors, need helpFollow

My friend has a new computer and, when she logs into the game, gets things at a high rate of speed. For example, multiple letters in words when she tries to type and the game itself is playing at such a high rate of speed that it's virtually unplayable. We think we've figured out that she has a dual-processor setup that is the problem but can't figure out how to make one of the processors stop running when she plays the game. She's running Windows XP. Can anyone help? Thanks in advance.

Thanks, that fixed it! ^^