Limited Connectivity

[#1]

Hi,
We've just set up our router and everyone in my house can access the internet except me.
When I try to connect, it takes a while and then an error message comes up which says 'Connection unsuccessful - if you are connecting to a wireless hotspot, you might need to open a web browser to finish connection'. If I go into my network and sharing center, I can see that the signal strength is excellent but my access is Limited Connectivity.
I tried switching off my laptop and using a wi-fi dongle but then I can't locate the plusnet connection at all.
Does anyone have any idea how to fix this?
Thanks!

[#2]

welcome to the forum.
Is your laptop by any chance an American one?  as they are restricted to channels 1 to 11, the EU ones use 1 to 13, it might be that your router is set to say 12. 
What router do you have, then some one can tell you how to change channels.

Another thought how close is your laptop to the router, as you say you have several connected with no problem, perhaps they are a lot closer to the router than you

[#3]

If you have a search, this has been covered very recently.
I'm guessing you have a Vista PC?!
Paul