When you encounter this failed update error on your Nokia Lumia.  It is best to download the Nokia Care Suite tool which is free, and will update your phone without errors.  Here is a link to the download tool.  This is may fix the  8007000d) failed update error on your LUmia 920, 925, 820 etc. hard reset Lumia 920 http://www.softpedia.com/get/Mobile-Phone-Tools/Nokia/Nokia-Care-Suite.shtml Error code 8007000d is about image validation. There is a mismatch between what is on the device and what the update is supposed to install to. The cause is likely one of 3 things:  

  1. Device did not come from a retail environment (was an engineering device, provided at a promotional event).
  2. The device image is corrupted.
  3. The image was intentionally manipulated. Something was done to the device to manually change its configuration.

Note: This is by far the least likely scenario but possible.   To fix this:   • Power cycle the device and then download the update again. • If re-downloading did not help, you will need to reset your phone. Go to Settings, look for System and then go to Aboutand tap Reset your phone. Give this a try and if the reset did not help then, take the device to a local Nokia Care point so that a specialist there will check it.   On the other hand, you can visit  http://discussions.nokia.com/t5/Accessories-Car-Phones-and-Other/List-of-Nokia-Lumia-820-Compatible- to know the lists of compatible MicroSD cards for your device. Prices may vary depending on the retailer.