Cannot access MMC after making local computer snap-in changes

Many changes were made to the local computer snap-in and they affected all
accounts under the policy. Now i cannot gain access to the MMC to make any
more changes, not to mention the administrator account has somehow vanished
from the Login screen.
I am assuming that if i had taken the administrator account out of the
snap-in i would have the ability to administer the other acocunts without
subjecting the administrator account to any other of the poliicies.
Does any one know of any work arounds for this problem so i can have author
mode to the MMC once again?

Thank you.