Unable to delete a user account
I bought new MacBook Air about one year ago. That time I thought I wanted to start from the scratch and choose what to to transfer, without transferring everything from my old macbook. Later I changed my mind and transferred old account with settings and all to the new macbook. I use the 'old' account for everything and I would like to get rid of the 'new' account. However, I can't remove it. I've tried to remove it through System Prefereces --> Accounts, but nothing happens. When I try to remove, I asks the confirmation if I really want to remove, I answer Yes and then nothing happens.
I've tried to solve this problem even with Apple Support, but nothing works. The account is just stuck. The 'old' account has different name but same AppleID.
Any ideas what I could do?
MacBook Air (13-INCH, MID 2011), Mac OS X (10.7.5)