Hello. Firstly, welcome to your third day on the blockchain. Your wallet was "registered" the day you registered your account. I'm looking at it right now. If you're attempting a transaction, you must be signed in with your Active Private key. It's likely you're signed in with your Private Posting key. Sign out and sign back in using your Active key. That should clear things up.
While I got you, never ever ever ever ever input your Master Key. Posting, voting, commenting, etc requires Private Posting key, that's it. Wallet transactions require an Active Private key. Neither require the Master. Master keys are strictly for editing your other keys and should be saved on paper only.
I hope this helps. Cheers!