DFU mode won't bypass the activation screen, only typing in the id and password that it's linked to in Settings > iCloud > Find My iPad (or potentially logging into that account on http://www.icloud.com and removing the iPad from it) will let you re-activate the iPad.
iOS 7 and activation lcck : Find My iPhone Activation Lock: Removing a device from a previous owner’s account
Is it your account that it's locked to, or was the iPad bought second hand ? If you bought it used and it's locked to the previous owner's account then you will have to contact the previous owner and ask them to remove the iPad from their account.
If it's your account then on the activation screen do you not have the first letter of the account and the provider that it's linked to - if you do then do you remember having an account with that id ? If you don't then might you have any of the account's downloads in your computer's iTunes library : Recovering a forgotten iTunes Store account name ?
If not then see if you can find the id via http://appleid.apple.com : Apple ID: How to find your Apple ID