Internet doesn't work, but I'm still connected???

I have a Vista 32-bit OS. Ever since I hooked up the router, whether through hardwire (computer>ethernet cable>router>cable modem) or wireless, several times a day, ever few hours, I will no longer be able to open web pages, but I will still have a full connection and all of my messengers will still work. I have tried everything I can think of to check, scan, etc. Nothing seems to solve the problem. There are 2 other computers that connect to the router and they have not had the same problems. One of the those computers is running Vista as well. Can anybody help me out?

 

Please CC your reply by email as well b_hall21@hotmail.com.

 

Thank you!