windows - I've lost access to my encrypted files

I have an account on Windows Server 2008 R2, which at the moment I am using as a desktop.

I had certain files encrypted under a standard user account.

I changed my password, and then lost power without logging off. After logging in again I was no longer able to access those files. Changing the password back to the original did not help.

I have imported my backup certificate to the personal store with the correct password, although this did not grant me access.

What can I do?

edit: Is this because I did not backup my certificate/key after changing my password? Have I now lost access?

Answer

Unfortunately, Windows is doing its job by denying you access with your old key :/ Windows requires a new key with a new password when it encrypts so someone with an old key gets locked out, just like a dead bolt.