OK, contact the manufacturer, or take it back. Does your ISP have an option for WIFI gateway? These things are pretty cut-and dried, so if you having issues, I am certain the instructions were not followed 100% of the way.
Stay with me:
You have the ISP "modem" or gateway. That is connected to the network, and it is good. Take a cable, and connect your laptop (windows 7) device and browse, does it browse? If yes, then take the same cable, and disconnect it from the laptop, and connect in the wifi device. Now, using another cable to connect to the WIFI, connect your laptop into the WIFI USING A CABLE! So, you should have two cables, a "modem" or gateway, a WIFI gateway, and a PC. Does the PC browse? Run the CD now!