1. Right click on My Computer, and select Properties.
2. Now click on the Advanced tab.
3. In the section labeled 'Startup and Recovery' click on the button labeled 'Settings'.
4. In the system startup section at the top of the dialogue box, click on 'Edit'.
This will open a file in Notepad - the file is actually called 'boot.ini' but don't worry about that.
Look carefully for a line in the file that relates to the Windows XP setup routine, and delete it.
Now save the file, close your dialogue box, and restart your machine - all should be well.