All is now working. Here is what I did: I removed the ethernet cable connecting the Cradlepoint router to the second (Netgear) router, and connected it directly to the computer. I really believe that the cable from the Netgear router to the computer is faulty, so I will buy another one. I use the Netgear to give the wireless signal a wider range than the Cradlepoint provides. Zep, I checked the TCP/IP properties, and it was not checked to Obtain DNS server address automatically. Instead, it had the ip address of the Cradlepoint router entered. I changed it, following your instructions, and kept losing the connection, so I put the setting back as it was. I think there is a reason I had it that way. I am using Open DNS on the router, and I think the instructions were to set it up that way. At any rate it is now working, so I'll leave well enough alone. Oh, yes, the wireless is working also. Thanks to everyone for your suggestions.

One possibility is that it's trying to connect to another wireless router in the area. This can be especially problematic if you and your neighbor both kept the default router names but used different security settings. Depending on where the routers are and where the laptop is, the neighbor's router may be giving a stronger signal. check your router's logs if you can. That may give you a clue about whether you're trying to connect to it instead of a different router. Many routers have a web interface for management (and please make sure you've changed it from the factory default password). Open your network connections, right click the wireless connection and select properties. Select the Wireless Networks tab and look at the preferred networks area. Make sure your router is the only one showing. If you have others showing, select them and choose remove.

I would start by making sure my anti virus is up to date with the definitions, then run a full scan. After I would run a full scan using the free program Superantispyware. If that fails to clear your problem use the link below. It looks overwhelming but just go through line by line and you will do just fine. Let us know how it goes please. Here is a link that might be useful: MS troubleshooter

Thanks, mikie. The minidump file must be normally sent automatically because I found the history in the Problem Reports folder; but this time it wasn't sent, and asked me if I wanted to send it, and not knowing what it was or what to do, I didn't send it. : ) I will from now on. It seems every morning when I power up the computer, it automatically connects to the public network, eventhough I'm sure I programmed my computer to open on my private one. I'm embarassed to say that I can't seem to remember where to find things on my computer, for instance, to show me where to tell it to open with my private network. Any idea? Once I work up the courage to add the MAC addresses, I'll try the filtering again. The tech support told me that I had entered the wrong address, but I think it was that I hadn't entered ALL of the addresses for both computers and the printer; but had only entered my laptop address. Thanks for your help, much appreciated.