1] Run CHKDSK Using CHKDSK is also one solution that is proven to be effective to fix the Invalid MS-DOS Function issue. To run CHKDSK, do the following: Press the Windows key + R.

MS-DOS was the early operating system for IBM PC-compatible systems, before Windows fully took over the PC landscape. MS-DOS Editor was included the 1991 release of MS-DOS 5.0 as the new default text ...

C:\Windows\System32\config.nt The system file is not suitable for running MS-DOS and Microsoft Windows applications. Choose ‘Close’ to terminate the application.” “16-bit MS-DOS Subsystem ...