The Microsoft System Configuration Utility (MSCONFIG) is a program that comes free with Windows XP and Vista. This tool allows you to select which items you do or do not want to load when your computer boots up. This can be very handy when trying to diagnose boot problems or software conflicts.
To access this program just click Start and type MSCONFIG into the run dialogue box.
For more information on how to use MSCONFIG read more at about it at netsquirrel.com