Important Notice

The pages on this site contain documentation for very old MS-DOS software, purely for historical purposes. If you're looking for up-to-date documentation, particularly for programming, you should not rely on the information found here, as it will be woefully out of date.

     /X: CPU in protected or virtual mode (CV1301)
 
     The DOS extender was unable to switch to protected mode.
 
     One of the following may have occurred:
 
        ■ OS/2 is running.
 
        ■ An EMM driver is running in protected mode.
 
        ■ A protected-mode application is running.
                                    -♦-