Mac 10.7.5 WONT CONNECT TO INTERNET!! PLEASE HELP!!!!

Hello,

I woke up yesterday an was unable to access the internet. However, I have full signal strength. I have Macbook pro 10.7.5

I will explain all the things I have done. Maybe someone who has had this problem could help me!! I would be forever grateful.

Every time I attempt to use firefox or safari I receive this message: “Server not found.”

First, this issue has nothing to do with my router. I am using my old mac and am accessing the internet fine. I also went to my school and everyone else was able to access the internet except me.

Second, I have attempted to connect to the router via Ethernet cable. The computer detected the connection. Showed a green light in “network preferences.” And was still unable to connect to the internet. This has me worried.

Third, I can see my room mates mac in my “shared” area in finder.

These are the trouble shooting steps I have taken, noting has work yet:

1. removed Wifi in network preferences and re added it
2. Renewed DHCP Lease
3. Deleted all preferred networks, all keychain entrys, etc. and restarted
4. At startup, held down cmnd, option, R, P to clear
5. Removed systemconfiguration from Library> Preference

PLEASE HELP MEEE!! I am stumped.

Thank you in advance!!