I was experiencing a similiar problem when I went from XP to Windows 7. I could not get my wireless adapter to connect to the internet, though it appeared that I was solidly connected to the router.
As I struggled to find a solution, it dawned on me that I kept missing a simple but important configuration query setting: Public Network vs. Home Network
...well say no more! Once I clicked on Home Network and answered one or two simple questions, I was once again flying high online!
Its the little things in life that matter!