Int 2F Fn 9900  U - Dos Navigator Ii - Installation Check                  [l]

   AX = 9900h

Return: BX = 444Eh ('DN') if installed
       AX = number of DOS Navigator executions
       CL = child process exit code
       DX = version number (see #3759)

Notes: old versions of DOS Navigator II always returned AH=1, while newer
     ones return AH=0 and store AL in the DN.FLG file
Program: DOS Navigator is a multi-window shell for MS-DOS by RIT S.R.L.
     DOS Navigator(TM) is a registered trademark of RIT S.R.L.

See Also: AX=9901h,AX=9902h,AX=9903h,AX=9904h,AX=9905h,AX=9906h

(Table 3759)
Values for DOS Navigator II version code:
 2100h version 1.35
 2141h version 1.41
 2150h version 1.50