While this may explain why you're having the error, the following will probably get you back up and running:
1. Access the recovery options at startup
2. Use the command prompt option
3. Type: net user Administrator /active:yes
4. If you see "command completed successfully," then type: exit
5. Reboot the computer
At the Windows login, you should be able to choose the Administrator account. If you can log into that just fine, then you can make a new user account for yourself (don't use the Administrator account permanently), move your data from the old user account over to the new one, and then delete the old account that you couldn't log into.