Vista - "apparently" i'm not connected?

hi i've already seen a thread on this, but there weren't any answers and i couldn't reply. so anyway i have the same problem my PC is connected to the internet, the icon shows so but the network and sharing center says im not connected, but then again hte network map shows me connected. so how can i sort this out? i dont want to get annoying messages asking me to connect all the time when i am.

i went to someone's house and their LAN connection wasnt being picked up on my PC but was on their's, so i changed a few of the settings in the TCP/IP settings place, although i'm pretty sure i changed them all back, so now im back and the pc doesnt think it's connected to the internet, this has happened with 2 routers that are working fine. so can anyone help?