1. Navigate to the 'Resources' section of this article and download the 'RemoveWGA 1.2 program.' (It's free.)
2. Double click on the program (no installation required) and it will tell you WGA is running and ask if you want to remove it. Click 'Yes.'

3. The program will ask you to reboot your computer. Click 'Yes.' When the computer reboots, after you log in, you will see a prompt from Windows asking if you want to run RemoveWGA. Click on 'Run' and it will remove all traces of the Illegal Error Message in just a few seconds. Enjoy an illegal-error-messages-free screen!