Hi Elizabeth,
Welcome to Microsoft Community. I will surely help you.
To understand the issue better, I would need more information from your end.
- Are you using a Microsoft Account or Local Account?
- Is the computer connected to domain network?
If you are using a Microsoft Account, I suggest you reset Microsoft Account password and check if it helps.
http://windows.microsoft.com/en-us/windows/what-do-forget-windows-password#1TC=windows-8
Hope this information helps. Reply to the post with an updated status of the issue so that we can assist you further.