INT 13 - ScanBoot - INSTALLATION CHECK

	AX = 5342h ("SB")
	CX = 0001h
	DX = 0000h
Return: CF clear if ScanBoot installed
	   AX = 0000h
	   CX = serial number ("SW" if shareware release)
	   DX = version
	   BX,SI,ES destroyed
Program: ScanBoot is a virus-detection TSR by PanSoft