met100,   Places to look to see if your Connection is enabled   What virus program and firewall are you using? I have see virus program cause problems with connections.   Can you run Finding System Information REMOVE YOUR PRODUCT ID and REGISTERED OWNER, if using XP, run an ipconfig /all log and post it back here.     Rick  
I recently lost network connection using the built-in Intel(R) WiFi Link 5100 AGN. Stupidly, this happened while I was still under a Service Contract, but due to the holidays, I put it off and the contract expired the middle of December.  I have a Studio 17/1745, I disconnected the internal WI-fi card and use a USB D-Link N and I now have WI-fi. Should I purchase a new internal WiFi card and if so which one. 
Intel(R) WiFi Link 5100 AGN installed in a Studio 17/1745