Int 2F Fn 1600  - MS Windows - Windows Enhanced Mode Installation Check    [W]

   AX = 1600h

Return: AL = status
       00h neither Windows 3.x enhanced mode nor Windows/386 2.x running
       01h Windows/386 2.x running
       80h XMS version 1 driver installed (neither Windows 3.x enhanced
        mode nor Windows/386 2.x running) (obsolete--see note)
       FFh Windows/386 2.x running
   AL = anything else
       AL = Windows major version number >= 3
       AH = Windows minor version number

Notes: INT 2F/AH=16h comprises an API for non-Windows programs (DOS device
     drivers, TSRs, and applications) to cooperate with multitasking
     Windows/386 2.x and Windows 3.x and higher enhanced mode.
   certain calls are also supported in the Microsoft 80286 DOS extender in
     Windows standard mode
   this function served as the installation check and AX=1610h served to
     get the driver entry point for XMS version 1, which is now obsolete.
     Use AX=4300h and AX=4310h instead

See Also: AX=160Ah,AX=1610h,AX=4300h,AX=4680h
Index: installation check;XMS version 1