open command prompt(start>run>type cmd and hit enter) type
ipconfig /all
this would give you all the details of yout network card along with ip addy and default gateway. ..make sure nothing is disbaled and you have a valid ip , gateway and Dns server.
If IP is 0.0.0.0 or 127.0.0.0 or 169.254.xxx.xxx then its a Connection or isp problem.
if you get a valid IP , a default gateway and a DNS server , try and ping all these by using the ping command for eg.
ping xxx.xxx.xxx.xxx
if you use a router ping it ir enter its UI(user interface by using the dafault gateway).
also try repairing and renewing your ip
ipconfig /release
ipconfig /flushdns
ipconfig /renew
if this does not help ...try this
netsh reset winsock catalog
at command prompt and restart
delete all cookies,temporary interenet files, check norton if its blocking any ports.
get firefox and check if you get internet connection with that.
check if you can get online with messengers (any).
check windows firewall , temporarily disable it and then check connection.
if its a problem with just IE ,, update it.
disable norton internet security plugin from IE from internet options>programs>manage addons.
if nothing helps , uninstall norton:-))
Update:
probably a prob with norton , uninstall it ion safe mode. or use the tool from norton itself to uninstall it
http://service1.symantec.com/Support/tsgeninfo.nsf/docid/2005033108162039
here is a free AV if you wanna use it (Avira AV)
http://www.free-av.com/