Wireless connection problem -authentication service unknown

I need help. I have two pcs and cannot connect to the internet with my second one. I have spoken to NetGear directly and they told me it is a problem with my computer. I have Windows XP and get an error message when I did what the guy told me. Error 1747 authentication service unknown. Everything else looks like it is working. I thought maybe I might need an upgrade on my older computer but it’s not that old. Any thoughts?? Thanks!