For anyone who might be interested in how Bigpaws solved this problem (and he did) here goes:
I realized when I got to the office that I needed to get on the forum to get Bigpaws' instructions, having not printed them out. As I take my Omnibook laptop with me everywhere, I set it up in the front ofice next to the offending desktop machine and tried to get on the internet so I could get his instructions. It would not find an IP. So I took the Omnibook back to my back office, which has a Buffalo wireless router, and tried it there and it got an IP right away. I concluded that the Netgear router in the front office was still not working right, despite having had it worked on by an expert for an hour or so on Friday, updating its firmware. I had to fix that before I could fix the desktop's wireless.
I took the small Buffalo router from my back office and moved it to the front office. I did this and then my Omnibook got on fine in the front office area. Then I booted up the desktop, finally ready to do BigPaws' fix (my mind for some reason was certain that the desktop was messed up as the day before it would not write the wireless configuration to disk). But first, on the off-chance that the problem was the router and not the machine, I tried to get a wireless IP on the desktop off the Buffalo - before operating on it. Good thing I did that. It got an IP just fine.
So now, what to do about my back office, since the Buffalo was out front? The only wireless use in the back office is from my Omnibook. The front office has four computer on the wireless, and a copier (scan) and a wired computer, all running off one router. I took the Netgear (by the way its the top of the line Netgear, I think) router back to my office and plugged it in and my omnibook got on fine back there. I then tried to send a scan on the Xerox and it worked fine. I tried the wired computer and it worked fine, as did the other wireless computers.
My conclusion is not very favorable as far as Netgear is concerned and I am going to order another Buffalo WHRG 125 router. Its about $40. The Netgear was almost $200, if I recall correctly. No idea why it would power some of the wireless computers but not that one. I had it in the front office area because, it being bigger and more expensive, I thought it better. Silly me.
Anyway, thanks again Bigpaws.