If you ever delete an account from Windows 10 BUT FORGET to FIRST delete all the fingerprint data belonging to that account, the fingerprint data stays forever in that specific device. The only way you can create another account and use your fingerprints to login again is to get new fingerprints. 8*)
But there is a fix! Following the threads all afternoon I eventually came across this thread on Microsoft’s support blog. https://social.technet.microsoft.com/Forums/en-US/93a122ff-3455-4b29-b3e8-2b72d49d19e3/windows-81-delete-all-fingerprint-data?forum=w81previtpro
DELETE C:\Windows\System32\WinBioDatabase\[GUID].DAT file and then restart the computer.
I had to boot into a Linux partition to get enough “administrator rights” to delete the files, but once deleted I could once more use the fingerprint functionality.