INT 16 U - PCIBM PC Tools v5.1-8.0 DESKTOP - INSTALLATION CHECK AX = FFEFh CX = 0000h Return: CX = ABCDh if PCIBM PC Tools DESKTOP.EXE installed BX = segment of resident portion AX = ??? (v5.1/5.5 only) SeeAlso: AX=FEEFh,AX=FFC5h,AX=FFF3h