Surely this should not be able to happen?

I upgraded my PC from 32 bit to 64 bit, and during the process my programmes and files were obliterated. I had backups of the passwords on an external drive so I knew I'd be able to restore them. I downloaded the free version of Access2, clicked on the new desktop shortcut to open it, but it goes straight to the logon window. Entering my master password, which I know is correct, all I get is "invalid user name or password". User name I hadn't changed from Administrator. So I uninstalled and tried again, but it still locks me out. I deleted all the .cfg files but no help

This is serious as I now cannot get at any of my passwords. How do I get the programme to work please???