Starrtup Error

Okay, I have been trying to sort out some problems on my girlfriend's dell. She insists on using Windows XP, and unfortunatly, I am only familiar with 2000pro that I have on my machine. She is experiencing a popup error on startup:

Data Execution Prevention
To help protect your computer, Windows has closed this program.
Name: WMI
Publisher: Microsoft

When I close this, I get the following error:

WMI
WMI encountered a problem and needed to close
and asks for an error report

which leads back to the first message, and so on and so on and so on... and I cant get rid of it... What is this message exactly? what is WMI? What is going wrong with it and how can I fix it?

 

Does she have sp2 installed? If so, check here, http://support.microsoft.com/kb/875351

Steve