I shut windows down while it was going through a series of updates. When I tried to start my computer again it is unable to load windows. The Compaq brand logo comes up, followed by the the XP logo---then the screen goes black, and for a quick second an error message appears that I cannot fully read---followed by the Compaq logo. It is stuck in a loop of some sort because it continually does this. I am not sure what I can do to avoid this cycle. I was wondering if you knew any ways to avoid this.

Yeah ,don't shut down you computer in the middle of install updates ..
also look here .
http://aumha.org/win5/a/shtdwnxp.php