Locked out of admin account after deleting computer from Active Directory

Hello,

I am the local administrator for my network. I was cleaning up my AD list of computers and accidently deleted a computer I didn’t want to delete. I went to the machine and could not login admin account under the domain or local computer. I unplugged the network cable and was able to login to the computer with the admin account. I then joined the computer to a workgroup I called Temp, with the intension of adding the computer back to the domain after rebooting. When I rebooted the computer the admin account was again locked out. I have tried loging in under administrator, domain\administrator, computername\adminstrator, etc. I am ready to f-disk the machine and reinstall windows. Any suggestions?