INT 2F - F-PROT v2.x - VIRSTOP - ENABLE/DISABLE BOOTSECTOR READ CHECKING        
	AX = 4653h ('FS')
	CX = 0007h
	BL = new state of bootsector checking (01h = disabled)
Program: VIRSTOP is the resident virus-checker from Fridrik Skulason's F-PROT
	  virusA program which attaches itself to other programs for the purpose of duplicating itself.	Viruses often (but not always) contain harmful code which is triggered by some event, after a certain number of reproductions, or on a specific date.  See also worm./trojan protection package