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