Hey bill!
I just installed pp2 on my non-tormach mill.
Pretty difficult and I only have it getting through to the main screen with very limited functionality. Have to figure out the pins now.
Any way, to enable pp2 USB dongle to install on my system I had to enable EFI boot. (In the bios) I had it set to just legacy but after a few reboots I started trying different things.
Also if you have multiple HDD's you need to unplug all but the one you want to install. It will error out otherwise.
I'm on a 5i25/7i77 with servos. I really wish they would stay away from so much py scripting and enable full linuxcnc capabilities.