My guess is that the best way to do this is to install Linux (e.g. Ubuntu 16.04) to a USB drive and make it bootable.
Then boot into Linux from that USB stick, and install Retropie following the instructions on the RetroPie website for x86/64 Ubuntu.

When you want to enter the world of RetroPie, simply boot the USB stick from the computer UEFI/BIOS boot menu.

I imagine that you'll want to use a fairly large USB stick to hold all the ROMs you wish to use.
64GB or even 128GB would almost certainly get you the bulk of the decent emulators.

press the button that you have assigned to start, then choose the configure input option.
It took me a fair while to find that :)

kodi-peripheral-joystick
kodi-inputstream-adaptive
kodi-inputstream-rtmp

already in unstable ppa for zesty 17.04
https://launchpad.net/~team-xbmc/+archive/ubuntu/unstable/+index?batch=75&memo=75&start=7599

@Ladyslayer0160 sorry to bring this up. I just got the same problem. I can't use the keyboard or joystick up and down after update. but works fine in terminal. Have you resolve this issure yet? Thanks!

@Al2017 you also have to copy the bios file to the USB drive.

Yes, the buttons have been working fine with jstest. After a few hours of hopeless resetting and deleting button configuration files, I tried a different port. Problem solved!

I still can't explain why a different port would let L & R work on ES while the actual inputs were detectable...

Now my only issue are phantom inputs, as discussed here: https://retropie.org.uk/forum/topic/8598/buffalo-controllers-phantom-inputs

@BuZz No problem, I understand you perfectly.

@Muffy https://github.com/retropie/retropie-setup/wiki/ssh

Also see https://retropie.org.uk/forum/topic/2861/guide-advanced-controller-mappings

@fieldofcows Any update on this yet? There was a thread (but I can't seem to find it anymore) that stated how to get this going. I tested it, but it wasn't working correctly when I tried to shutdown ES. I wanted to give it a go now and see if things have changed.

@RDaugherty get the id of another button from the config, and put that in the per rom config - eg input_enable_hotkey_btn = "9", so now another button will be hotkey, and select will work. The reason why select isn't working is because it's used for triggering retroarch hotkeys.

Old topic I know, but I created it so live with the bump! lol

So my 16-year old cousin brought his Pi Zero I built for him over to his buddies house and the sound wouldn't work. Regular consumer-style like 50" flatscreen (he didn't remember the brand/model), with the same cable he uses at home. After my other cousin had an issue with sound on an older ~32" Sony I've used hdmi_drive=2 on all of these. Any suggestions on what to try?

The elinux wiki says to also try adding:

hdmi_force_hotplug=1 hdmi_force_edid_audio=1

but I honestly have no clue what those do and haven't seen them referenced anywhere else...

@Floob I'm now running retropie 4.2 on pi zero
when trying to get my neo geo games to work i used to use pifba on 4.1 and it would work perfectly with my wired ps3 only one player now that I'm using 4.2 pifba games run perfect but my ps3 controller doesn't work right up=start down=select if figure that much not when i change emulator to lr-fbalpha controller works perfect but the games start to lag and not working perfectly i haven't tried bluetooth yet but i figure it will be the same PLEASE HELP BEEN STUCK FOR A WHILE

@saleh99 delete the config and reinstall retroarch from retropie-setup / manage packages / core

Thanks for the replies, I had it all wrong in my mind :)

Cheers!

@TMNTturtlguy thank you will give it ago

@Darksavior I believe I tried a few months back but no success there - I couldn't get neither Time Gal nor Road Avengers working on Daphne on the Pi. Had to settle for the PSX versions.

No problem!