How to Stop a C000021A Fatal System Error With a Blue Screen

1. Restart the computer, and press the spacebar during the computer's boot cycle to open the GoBack software's menu.
2. Highlight the 'Disable' option for the GoBack option and then return to the boot process. The computer should continue booting as normal. In Control Panel, double-click Add or Remove Programs. In the list of installed programs, click GoBack, and then click Remove. Follow the on-screen instructions to complete the uninstall process.
3. Go to the 'Start' menu and then select 'Control Panel'. Then choose the 'Add/Remove Programs' icon.
4. Click on the GoBack software and then select 'Remove'. A pop-up window will appear asking you if you are sure you want to remove the software. Select 'Confirm' and the software will be removed. When you restart the computer, it should be free of any errors.