Hi concord,
Definately check for virus and malware infection also make sure that you hard drive is not full the OS requires at least 20% to operate If no viruses are found and your hard drive is ok make sure you have at least 2GB of ram installed. Your computer may also be running out of virtual memory as well if you have 2 hard drives in your computer then shift your page file to the drive which doesn't have your OS and set the vitual memory values at both the same setting ie. minimum and maximum the same value this will also make a difference How to do these things can be found at the Microsoft help web site
galeck1947