Thanks. I've tried several different 1511 builds now and no joy. Also tried ESD from backup on C:, and the image created with MS Media Creation Tool. Every single one fails with 0x800f081f - the...

That's a nice tool but, it lists dates instead of build numbers?

I'm assuming that I need an ISO of Windows 10 64 bit, Version 1511 Build 10586.494 to run DISM on my corrupt system (upgraded from...