Dec 28, 2011
I recently buyed a samsung galaxy5 n it had a gmail a/c already logged in so i cant remove that a/c or download anything frm market. I tried to formate my phn that is also not plz do help me out.
UHH, it sounds like you purchased the phone from another user and not from a store. To get the old data out of the phone and have it set up like new out of the box, you will need to do a Factory Reset. After that you can enter in your own Gmail account, get one if you do not already have one, and be able to access the Market for purchases.

I am not familiar with your phone so can not tell you how to navigate in settings to get to the Factory Reset. On my phone it is Menu > Settings >Privacy settings and you will see the factory Data Reset button in that screen.

You will see some options about backing up your phone, but do not bother because you are going to start over with your own Gmail account so you will not have access to the back up.