After a fresh install of Windows 7 Pro. I can't get to the internet when login to my company domain using IE 8. When I log off and login to the same machine locally I can get out to the internet. Also, when login to the domain, using the ping command I get a reply from anywhere outside of my network.
This sounds like it might be a policy issue on your company network. It is possible that the computer just needs the domain policies updated. Try doing a start->run and type gpupdate /force and hit enter.
If a ping successfully gets out but web traffic does not, try pinging google.com then navigate using the IP address instead of the name. (type the ip address into the web browser)
If you are able to get to google using the ip address then you most likely have a proxy enabled (lots of viruses do this), or dns filtering on your internet connection. Contact your companies IT department either way and they should have a quick fix for you.
Additionally, if you upgraded your windows 7 installation yourself, then your IT department will most likely have to delete your computer object from AD and recreate it as your machine password no longer matches the DC's password. (The user password in only part of domain authentication)