XP Shutdown Problem

I have a XP WIN Home Edition that, until about 2 months ago, does not entertain the shutdown Windows utility. I downloaded the newest XP shutdown update from ZDnet and installed, yet this does not seem to help the problem. The company I bought thesystem from IBUYPOWER.COM will not communicate via PC for troubleshooting support. In WIN 98, I know there were fixes for this same problem. Maybe I am installing wrong. Please advise and Thank You!