Windows xp systems allow you to run games in verious compatibilitiy modes. find the games install folder and locate the icon for the game. right click the icon and select the compatibilitiy tab on the dialog that opens. in that dialog click the check box titled 'Run this program in compatibilitiy mode for:' and then select windows 98/ME from the drop down menu. click on aply and then run the game bu double clicking that icon. it maybe better to make a short-cut of the icon on your desk-top and setting compatibilitiy options in that one..
that will make the pc except the game better and run more stable as for slowing down the system goto the following url
http://www.freedownloadscenter.com/Utilities/System_Maintenance_and_Repair_Utilities/Bremze.html
Pete
February 2007