Can i use a Belkin F6D4630 instead of my F@ST2504n

Hi people

My router and my so called booster have been driving me nuts since i owned them, I have the router in my living room 5 meters away and the booster in the extension right next to my tv and xbox.
I never had a wireless router issues before only since i had this piece of junk, now i cannot even get a good signal to my xbox or tv which are meters away but round the corner.

Today i see a belkin F6D4630-4 v2 in the charity shop and i thought this could be the answer so i brought it for a fiver, got home searched the net found out i maybe able to use it if i generate the login and password. I want to replace my F@ST2504n with the belkin can this be done?? because i tried all the login and password with no luck no connection, i would like to replace the router rather than use my old as a modem and connect to it. is there any threads on setting up a belkin???

Also when i go to the login and password generator do i enter the password or pin number??

Thanks all appreciate the help j