Dell support may not help you with spyware or pest removal, so be sure you don't have such.
About two clicks from http://www.aumha.org/articles.htm is the XP Shutdown article for you to work.
We bought a new Dell probably 10 months ago, and recently when we restart it doesnt go furthur than the black screen with a blinking line in the top left corner. Usually I turn it off for awhile and keep trying and eventually windows will start. I was wondering what the problem could be and how I could fix it. Also, sometimes when I log out of a user (windows XP) or try to shut off the computer it will just freeze on a screen and you can't press the power button all you can do is flick the switch on the power bar.
Thanks for any suggestions.