Make sure to make the crossfire folder an exception to your anti virus. It could be your anti virus doing some mischief which is allowing this error to come.
This is also another method you can try. Right off the Z8 Forum.
Might be DEP.
Data Execution Prevention.
Turn that junk off by:
Right click on My Computer
Click on Properties
Click on the Advanced tab
Click on the Settings button in the Performance section
Click on the Data Execution Prevention tab
Check the box that I circled in red and hit apply, let me know if that fixes yo' computaz.