Some website work others DONT!

[Trojahnmann]

I have a problem that I desperatly need fixed heres the deal:

My internet wont let me get on certain webpages for instance i cant get onto Gmail.com however i can get to weather.com its simple things like that.  Im in college and I need to get into my mail and my courses through the internet however these sites dont work either.  My buddy who lives with me has no problems accessing these pages through his computer.  Just recently this began happening and its not the first time.  Can someone here please help me figure out what this problem could be.

Ps-  I reformated computer the get the internet working before when i had this problem but there were other reasons beyond that as to why i needed to reformat.

I use Mozilla but internet explorer has the same problem.!

[patio]

Ps-  I reformated computer the get the internet working before when i had this problem but there were other reasons beyond that as to why i needed to reformat.

This could be part of the issue...can tou be more specific ? ?

[Trojahnmann]

I had a trojan but thats long gone and my computer is healthy I just dont get this at all.  Only websites like MAIL or my college courses websites dont work. However they are perfect on my roomates pc.

[patio]

Are you running a firewall on that machine ? ?