I was thinking about other computers, to see whether ping to those works. But this actually sounds like something that happened to me a while back - both computers could ping everything else on the network, but they couldn't reach eachother.
I solved it by giving them both static IP addresses which were not the ones they'd had previously and then restarting the wifi interface on both of them.
@FaheemMitha I started as a kid, taking lessons for all my pocket money... then I grew up and didn't have the time, or had the time but not the money. I started again maybe 10 years ago and now I spend all my time and money there :-)
I have some health issues and riding really helps, too
@FaheemMitha But it helps that I have a co-owner, and there are some very good people boarding their horses at the same place so we help one another out in case anybody's ill or unable to get there for some reason
@Anthon I was rather surprised to see that coming from someone that had a fair amount of rep, but he may not be that familiar with the review process on SE sites. Also maybe much of his rep is from those types of answers on some of the other SE sites which I find quite annoying, when A's don't do much more then give you a lead via a URL or don't actually show a solution just make mention of one.