Sunday, May 1, 2011

WP7 Error During Update: 801812C1 -- Device Unplugged

UPDATE:  This issue no longer seems to occur with the latest update to the Zune software (4.8.2345.0).

The original thread is located at:

My Original Question:
I know exactly why it is happening, and this is the same problem I'm having with wireless sync.  All other functions between Zune and the phone are fine, as apparently they do not require the Zune or ZuneWireless device driver.

The WindowsPhone driver installation fails the same way on the initial, first try but then seems to complete normally every other time somehow.

The phone disconnects automatically before the Zune or Zune Wireless driver completely installs.  It takes upwards of 5 to 10 minutes before I get a driver installation failure with the "Device Unplugged" message.  I have no idea why it takes so long for the driver installation, but it's nothing I can seem to fix.


  • Is there a way to update this wait timeout of the phone during driver installation to be indefinite or at least much longer?
  • Is there a way to manually install these drivers so they are ready to use upon the phone's connection?
Note:  There is no reason to post a link to here as a potential answer.  The solution on that page has no impact on my problem.  It explains the issue I'm having, but the solution will not work because it assumes there was some error due to a non-repeatable problem.
My final response with a semi-answer after no help:
Sorry to see others having the same problem as me, but I knew it would come up.  The goal to fixing it is to reduce the time it takes to find the driver it is looking for.  It really has little to do with the phone or Zune, but instead actual Windows (at least in the fact that they apparently aren't going to update Zune to handle this situation, which I think they should).

If you are a semi-advanced user here are few things to try.  I managed to get mine to find the driver in time for about 1 out 5 tries by doing these things.  Once it finds the driver the first time, everything works smooth from then on.

Edit the Default Driver Search Location Registry Key
You will want to just pre-pend the Zune driver location to it.
Original Value:
New Value:
C:\Program Files\Zune\Drivers\Zune;%SystemRoot%\inf

Disable the Windows Update searching during driver installation

Note 1:  Make sure to notice you'll actually need to turn off two items (one in the steps and there is a Note in the heading to tell you about another one to turn off).
Note 2: If you are part of a real domain, you'll need to reconnect to that domain and reboot before the policy will be effective.  Otherwise, just reboot.



I tried your solution. After the connect to pc thing, it comes up as a windows mobile. I do not allow the computer to look for driver over the internet, so it just stays there as windows mobile(with no color,no driver installed) till the phone restarts and again 801812C1. HTC HD7, Windows Vista home

| Synergy |

I had this loop on A Nokia Lumia 800, but this is worth a try on any phone that has the issue as it's a 30 second fix..

Would try to update the phone with Zune (crap software) but would get an endless loop while installing the driver..

The loop would install the zune driver, then once installed would state 'Device Unplugged' before immediately restarting the driver install..

So.. What I did first to attempt to fix this was to unplug it, while in this loop and plug it into a different USB port.. It worked and the 800 driver was immediately installed.

Note: The USB I got it to work in was never previously used for this phone so the USB drivers on that interface/port were fresh.