How to delete a user from iMac after reboot, using os x install dvd to reset keychain

So, I forgot my admin password on my iMac recently and so i used the reboot with OS X snow leopard install disc to reset the keychain, but now on my login screen, it used to be just my account name, there is one called "Other" so i went into accounts in system preferences and tried to delete it but it isnt there? any help on how to delete this "other" account would be much appreciateed!

it is really annoying me

p.s. the "other account" isnt actually an account it says "Other" and when you click on it asks for your username and password...so i type in the admin accounts name and password (admin account is the only one on this computer), and it just opens up my admin account.

Just a little bit of extra info