INT 60 - RIFS - SERVER - INSTALLATION CHECK                                     
	AX = 0008h
Return: CF clear if successful
	CF set on error
InstallCheck:	test for the signature "RIFS" immediately preceding the
	  interrupt handler
Range:	INT 60 to INT 66 and INT 18,selected by scanning for 0000h:0000h vector
SeeAlso: AX=0000h,AX=0009h,AX=000Ah,AX=000Bh