I can access the router OK, and have turned off anything that even remotely looks like a security switch. I can run a laptop within 40 feet or so of the router, but three PCs that used to work OK with the old router will not even see the new router. One recognises it but cannot pull in enough signal to log onto it. It is as if the thing is very weak, which is funny since it is a N model which is supposed to be a better range than the old one. Maybe it is only a better range if the receivers are also N. If the receivers are G (which they are) they might not work as well.
I don't have a clue why the old one stopped working; nothing else has changed in the office where it all takes place.
I can change the signal by moving the new router around, so there might be inteference issues but with things the same, I have no idea why it has cropped up now.
I am going to buy another router, the best I can buy, and take this one back for a refund. I will just have to buy new N type wireless receivers for all the computers. Or else maybe buy new modems and connect the computers directly. Whatever, I am sure it will cost me more than I wanted to pay.
There is one type that is able to have bigger antennas fitted, maybe that will work for me.
I am surely sick of all the work...