The NTVDM CPU has encountered an illegal instruction.

The exact error message is as follows:

16 bit MS-DOS Subsystem



The NTVDM CPU has encountered an illegal instruction.

CS:0dee IP:1997 OP:ff b9 07 f5 ff Choose 'Close' to terminate the application.


This error began after I ran a third-party application to partition the hard drive, which required a reboot and did some damage to the files on the hard drive.  I ran chkdsk twice and everything is clear now except for this message which appears on boot because Windows 7 tries to load this start-up dll.

Can't find a "Windows 7" fix, I ran mfc /scannow which did nothing to resolve the problem.

Please help.




I would suggest you to perform a clean boot to check if a third party startup program or service is causing the problem. With the help of clean boot
you can disable the program or service to fix the problem.

Refer this KB article for more information:

How to troubleshoot a problem by performing a clean boot in Windows Vista or in Windows 7

Steps to perform a clean boot:
a. Click the start orb on your desktop
b. Type “msconfig” (without quotes) in the Start Search box, and then press ENTER.
If you are prompted for an administrator password or for a confirmation, type the password, or click Continue.
c. On the General tab, click Selective Startup.
d. Under Selective Startup, click to clear the Load Startup Items check box.
e. Click the Services tab, click to select the Hide All Microsoft Services check box, and then click Disable All.
f. Click OK.
g. When you are prompted, click Restart.

NOTE: Please ensure to start your computer in normal mode after troubleshooting. FollowStep 7 from the KB article mentioned above.



Afzal Taher-Microsoft Support.
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Question Info

Last updated July 8, 2020 Views 113,068 Applies to: