Home Forums Networks & Cross-Platform Networking Dell XPS - Airport Extreme Issue

I have an older Extreme ( V7.6.4 - purchased 2007 ) that has the 802.11.n wifi standard.

Now, I also have a house guest with a new Dell laptop (13" XPS) that uses the newer 802.11ac standard.

The Dell does not see my Airport Extreme router.

Thoughts?

Edit: And, I now got a rather disconcerting surprise. I thought I should check the Airport Extreme settings to see if I have done something like making the Extreme invisible (haven't configured for many years, so can't recall). However, I can't find out. The version of Airport Utility installed with my Mountain Lion 10.8.5 will not work with an older Extreme.

Boo, hiss, Apple.