This has been endlessly frustrating. I'm trying to go back to stock on my Lumia 920 because it doesn't look like Microsoft is serious about helping people on the Developer Preview who have the 80188308 error. I've tried dozens of times between my Surface Pro 3 and laptop, with every configuration I can think of. I've tried every USB port, turning off Firewall and Windows Defender, uninstalling/reinstalling Nokia Software Recovery, starting Windows without several startup programs, disabling duplicate "Lumia 920s" in the Device Manager, but nothing will get me past this error code. It gets to the installing firmware step and instantly fails every time. There's an unfortunate lack of information on the Internet as to what the error code actually means.
So here I sit, unable to update forward or downgrade my 920. Oh well...first world problems.