It is a 2 step process to connect to the internet over a network.
1) Connecting to the network.
Click Start (bottom right of screen), then click Control Panel, then click Network Setup Wizard. When it asks how you connect choose the middle option (This computer connects through a residential gateway or through another computer on the network). Once you complete the wizard Internet Explorer should be working.
There is also a Wireless Setup Wizard under Control Panel in case your 3Com card did not come with a setup CD. You did run the 3Com wireles setup right? If not that should be step "0". Some wireless cards require their own setup CD (mine) and some will work with the windows built in setup.
2) If IE is not working - Make sure everything in internet explorer setup is correct:
Open internet explorer and off the menu bar at the top choose:
Tools-Internet Options-Connections
Click on Setup and follow the Wizard instructions
It gets ugly here depending on how your Internet provider operates. One of the steps will be whether to dial a number or use your LAN connection.
Choose "Connect through a Braodband connection that is always on" the frist try. If that works you are done. If not you have to find out if your Internet provider uses PPPOE or some other annoying protocol.
If your wireless router is not connected directly to a broadband modem (DSL or Cable) then life gets more complicated. Post back for more instructions then.