OK, Instead of uninstalling StyleXP again just change the default boot to the Windows XP and the time to 0. To do this:
Right-Click 'My Computer' on the Windows Start Menu / Desktop. In the drop down list click 'Properties'
In the dialog box that opens, select the advanced tab and click the button shown here:

In the new dialog that pops up change the 'Default Operating System' drop down to the one that is shown below and the 'Time to display list of operating systems' to 1 as shown:

Now click 'OK' and 'OK' again and restart your computer, the Boot screen should now automatically revert back to default.