Trying to run DISM from bootable USB to repair Windows Installation...

Darkstrike said:

I've figured out that this install of Win10 has NEVER been upgraded! 0_o It's still running build 10240, which from a bit of research seems to be the very first version released to the public officially? That's crazy!

No, just very broken (or at least, windows update is). If the Upgrade Assistant completes succesfully you should end on 1803, build 17134.345.

So you're saying I would have to find an ISO using that exact same build number...?

If it doesn't complete, you could use the latest 1803 iso to do the in-place repair. It will just upgrade you to 1803 at the same time as performing the repairs. It is technically still possible to get the 1507, build 10240 iso direct from Microsoft, but you might as well upgrade/repair all in go.

Bree said:

No, just very broken (or at least, windows update is). If the Upgrade Assistant completes succesfully you should end on 1803, build 17134.345. If it doesn't complete, you could use the latest 1803 iso to do the in-place repair. It will just upgrade you to 1803 at the same time as performing the repairs.

I had tried to do that from a bootable USB, but from within the OS - it failed because some sort of uncloseable Windows Update window popped up in front of it about having to upgrade because of security. I had looked THAT up and it was legitimate, but it screwed up my other install when it popped up and interrupted it. It's not reappeared so far, so hopefully this Windows 10 Upgrade Assistant install will work...

dalchina said:

If upgrade fails and you wish to do an in-place upgrade repair install, yes, you would need an iso for that build. Readily available: there's a tool on this site, there's the MS download site, and a couple of others you could use.

And, after like 5 hours of waiting the bloody Windows 10 Update Assistant has failed at like 94% of the 'Getting Ready for Update' section....

'Something went wrong - 0x80070002'

Guess I'll start downloading the 1803 ISO...

Thanks for all the help guys - I ended up having to give up and wipe the machine. Cheers for trying though! :)