netgear wireless router adapter setup

Internet will not work?

I have broadband, my router is a "Speedtouch" and I'm using a four wire port "Netgear router. There are four computers in the house. This, connected with ethernet cable, a laptop that connects wirelessly, another desktop that connects LAN, and that will not connect. This is an old desktop with Windows 98. I'm using a "TP-Link" wireless adapter to connect to the Internet. Is working perfectly until a few weeks. Just stopped connecting to the network. There is a tray icon indicating that it is connected, but I just can not get the Internet to work. I reinstalled the USB software, I reconfigured the settings for the USB adapter. I have tried all kinds of tricks in recent weeks, but just does not do what they say.

I would like to consult the manual (if any) and call a product support line, or poke through the manufacturer's website.

netgear rangemax Wireless-N USB 2.0 Wireless Adapter