To set the program type of an executable file, specify one of the program types. More than one executable file can be set to the same program type on a single command line.
MARKEXE type filename.exe another.exe
Examples
To set WINDOWCOMPAT as the program type of MYPROG.EXE, type:
MARKEXE WINDOWCOMPAT myprog.exe
To set WINDOWAPI as the program type of several executable files, type:
MARKEXE WINDOWAPI marion.exe alex.exe