_DOS

_DOS is the operating system and command processor type.  Each JP Software 
command processor returns a different value depending on the operating 
system, as follows: 

    +---------------------+---+----+-------+-------+-------+-------+
    |                     |DOS|OS/2|Windows|Windows|Windows|Windows|
    |                     |   |    |3.x    |95     |98     |NT     |
    +---------------------+---+----+-------+-------+-------+-------+
    |4DOS                 |DOS|DOS |DOS    |DOS    |DOS    |       |
    +---------------------+---+----+-------+-------+-------+-------+
    |CMD.EXE              |   |OS2 |       |       |       |       |
    +---------------------+---+----+-------+-------+-------+-------+
    |4NT                  |   |    |       |WIN95C |WIN98C |NT     |
    +---------------------+---+----+-------+-------+-------+-------+
    |Take Command/16      |   |WIN |WIN    |       |       |       |
    +---------------------+---+----+-------+-------+-------+-------+
    |Take Command/32      |   |    |       |WIN95  |WIN98  |WIN32  |
    +---------------------+---+----+-------+-------+-------+-------+
    |Take Command for OS/2|   |PM  |       |       |       |       |
    +---------------------+---+----+-------+-------+-------+-------+
    

    
 This variable is useful if you have batch files running in more than one 
 environment, and need to take different actions depending on the 
 underlying operating environment or command processor.  If you want the 
 current command processor name, use _CMDPROC.