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When I try to run a Symantec fix here, I get the following error:

16 bit MS-DOS Subsystem
The NTVDM CPU has encountered an illegal instruction.
CS:393a IP:393a OP:ff ff ff ff ff Choose 'Close' to terminate the application.

How can I debug this?

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up vote 1 down vote accepted

The download is corrupt. The MS-DOS subsystem shouldn't be trying to run that file; It's a Windows executable. For some reason it's not being detected as a valid Windows application and being run in MS-DOS mode, but it's not a DOS application so it crashes.

Just re-download the EXE or complain to Symantec

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