Hopefully you read my post on WinRE: Media Install of Windows 8.1 (and Partition Problems!) and realize there is a problem with the UEFI Partitioning of Windows RE tools being 300MB.
I still stand by my Partition Recommendations of increasing the size of this partition, and this post will show how close this Partition is to almost working.
During the Generalization phase of Unattend, Windows Setup will try to move WinRE.wim from C:\Windows\System32\Recovery to where it needs to be, which is in the System Partition of BIOS MBR (Partition 1) or the Windows RE tools Partition of UEFI GPT (Partition 1).
This is validated by looking in the C:\Windows\Panther\setupact.log. Windows Setup will check the partition at offset 0x100000 which translates to Byte 1048576 (which divided by 1024 gives us 1024 KB)
Which incidentally is the Offset for our Recovery Partition.
Now apparently this fails and we have an error that there is not enough free space
[setup.exe] winreMeetPartitionReq Not enough free space req = 0x120F8B78 avail = 0x11CFE000 offset = 0x100000
It requires 0x120F8B78 (303008632 Bytes = 288.97 MB) but we only have 0x11CFE000 (298835968 Bytes = 284.99 MB). So this partition is 4MB too small to be used properly
Maybe it is the 15MB of NTFS overhead that wasn’t accounted for, but it was close.
For grins, here is what a properly sized Windows RE tools looks like in setupact.log