Historian wants password

Just installed Historian 5.0 for a customer. I was logged in with full administrative privileges to do it. Now when I try to open Historian Administrator, it asks for a password. The same password that works to log on as the administrator doesn't pass muster with Historian. The same computer runs a View Mirror runtime on power up, but even if I shut down the View runtime I get the same result with Historian.

Any suggestions?