I have a problem with my wireless connection...

I bought a 360 just recently and a friend gave me a mircrosoft wireless network adapter for it. When I first installed it, it worked well and without hazzle. About a week ago it started to take more time to connect to live and then it disconnected at certain points. I tried to reconnect but I couldnt. I been having this problema for about a week and I dont know what to do, i have already played with the settings and did some things with the router but i dont really know much about this stuff. I believe the problem is on the router more than the adapter, so if someone can please give me some advice or tips on what to do in this situations it would be appreciated. thanks

Google the router you have, and find out how to set it up properly.

There are too many issues possible, and not enough information for us to be able to help.

And I say this as someone who's done hundreds of networks.