So Today, I attempted to access my NAS over SMB (\\files) on my network workgroup. The window hung for a moment, and a dialog I've never seen before when connecting to a share, with the title "Select Certificate" popped up. ultimately, I'm unable to access my shares from this box.
I can see that a certificate windows registered for my local user has expired. it was issued by me to me, the very definition of self-signed. The certificate has no trusted root certificate (not surprising). Windows tells me I have a private key associated with this certificate.
I did not knowingly create a certificate, and I've never known SMB to just fail every year just because a cert expired (or really even to require one at all, if you are not on a domain).
A reboot didn't clear the issue, and I'm having difficulties finding information on generating a suitable replacement.
Any ideas?
UPDATE:
It appears I can get to shares using the FQDN, without any request for a certificate. DNS resolution works as well for hostnames as fullnames on my LAN, so I'm thinking something has remembered that destination, and needs to be flushed. any ideas what?

filesand inside both Windows Credentials and Web Credentials), reboot, then login again to\\files.