jjja, You could go to the link below and download "XP_Fix.EXE".
"This installaton program will reinstall the missing or corrupt Windows XP system files command.com, autoexec.nt and config.nt. The absence or corruption of one or more of these files causes a "16 Bit Subsystem" error.
We recommend that you download this file and save it to your desktop or to another location where you can find it. Double click on the file to run it once it's downloaded. If problem reoccurs in the future, simply re-run this program".
Another fix some have used is to do a search for autoexec.nt You will probably find it in C:\WINDOWS\repair. Copy and paste it into C:\WINDOWS\system32.
The 2 links below explain what may be causing the problem (Malware).
Hope this helps,
I've been trying to install my son's computer games, but some are installing no problem,and others I get an error message that says...
C:\windows\system32\autoexec.nt The system file is not suitable for running MS-DOS and Microsoft Windows applications.
I don't know why this is happening because I had these installed before on this same computer.
I tried microsoft support to try and resolve but that didn't work. I have Windows XP.Please help if you can.Thanks.