Useraccounts after upgrade to SP2

I have Visa Home Premium x64.
I have 1 useraccount.
After updating to SP2, I now have 2 identical useraccount in my login picture.
When I enter useraccount in the control panel there is only 1 account.

What went wrong ?????

Do you have automatically logon set on startup?If yes disable it.
Read whole tutorial:http://www.vistax64.com/tutorials/66966-logon-automatically.html