Locked out of RDM after Windows 10 update today

The Windows 10 update that I installed this morning took a long time and was a major release, I even had to reinstall RSAT because the tools disappeared.

When I went to launch RDM, it asked me for my windows credentials as I have it setup to do, but every time I try to login it tells me I have an invalid password entered.

I've checked my account isn't locked out, I've tried repairing the installation and rebooting but nothing so far has worked.

How can I regain access to it?

Thanks!