I figured some of it out
unzip the dll`s from the 32bit dir into your hdsdr dir
then get ExtIO_RTLSDR.zip (for the 2Msps version) or get ExtIO_RTLSDR_1msps.zip (for the 1Msps version)
MD5 for ExtIO_RTLSDR.zip = 5013953E7A0055AF8950E0A934714B08
MD5 for ExtIO_RTLSDR_1msps.zip = AA843EBDC6C558644BC24E6AD0CC4570
but those are NOT the newest one as there is no GAIN control when you clock on the "ExtIO" button in HDSDR
There is another File somewhere that someone has that fixes this problem so we get the Hole (fix) AND gain control from within the HDSDR ExtIO Button.
if someone finds it please post it as some people still like HDSDR