Giving higher priority could work.

To change the priority of a program in Xp, go to the task manager (usually you can call it by pressing CTRL-ALT-DEL).
Then click with the secondary mouse button (usually the right one) and select the item Go to process (it should be the last one in the popup menu). Now you should be in the processes tab, with the right process selected. Again click with secondary button and select Set priority in the menu, then you can choose the priority that you want.

If you are rendering an animation, you must set the priority of the batch render and not of Maya, so you have to start the rendering and then go directly to the Processes tab of the task manager and search for the right process (it doesn't show in the Application tab) and change priority.

Hope this helps...

Bye!!