One of the most common requests from customers now is that they want to move from BIOS -> UEFI when upgrading to Windows 10. As of Configuration Manager 1610, it is possible to switch from BIOS -> UEFI out of the box with the new Task Sequence variable TSUEFIDrive. Read more about how to configure this variable here.
For the customers that are still on the Windows 10 1511 ADK, but have upgraded ConfigMgr to the latest (as of 2016-12-27) 1610 version, I have noticed a frustrating error upon the first reboot following the format of the disk when converting from BIOS -> UEFI.
What I have seen is that after the first reboot, the Task Sequence will fail with this error:
Failed to validate for boot image staging
Failed to stage a boot image xxxx. Element not found (Error: 80070490; Source: Windows)
Failed to reboot the system. Error 0x(80070490)
Failed to initiate a system reboot. Element not found. (Error: 80070490; Source: Windows)
Fatal error is returned in check for reboot requrest of the action (Restart in Windows PE). Element not found. (Error: 80070490; Source: Windows)
An error (0x80070490) is encounteed in execution of the task sequence.
The solution is to uninstall the Windows 10 1511 ADK and install the Windows 10 1607 ADK. Download it here.
If you want to read more about BIOS -> UEFI conversion I recommend you to visit Nickolaj’s blog post series.