Could you say more details about "your network"? Is this your home router we are talking about? What type?
It can be so many things, Microsoft even made a page with this title:http://windows.microsoft.com/en-US/windows7/Why-can-t-I-connect-to-a-network
You say that it asks for password, and it is accepted. This means to me that the connection between your computer and the router is successfully established.
You should check if your network interface gets an ip address from your router by starting a command line window and typing: