I should have written this post a while ago but haven’t had time yet. When using the new BIOS-UEFI conversion solution in Configuration Manager 1610, https://docs.microsoft.com/en-us/sccm/osd/deploy-use/task-sequence-steps-to-manage-bios-to-uefi-conversion If you are still on 1606 or earlier you can still use this method: https://ccmexec.com/2016/07/switch-from-bios-to-uefi-seamless-using-configuration-manager-ts-in-6-simple-steps/ I have seen the below error 0x80070490 when the computer tries to restart the first…