Have you tried clearing cache, history, etc., of the browser, or using a different browser?

Have done all weekly. Except for using different browser. I have questions about Chrome, but would rather focus on all the different messages from Win Network diagnostics. I wouldn't think having a different browser would cause the diagnostics to tell me I don't have a valid IP address for Ethernet. I know IE is the worst, but I have enough problems to focus on with out maybe causing more by switching browsers if it's a network settings problem. One thing at a time.

I know it's one of those silly questions, but are you trying to connect to the right Network? Occasionally my Laptop will pick up on a different Network (I have two) and I can't connect. I then realize that I'm trying to connect to my Guest Network and would need to enter a Password. I get messages like you're getting, it doesn't tell me to enter a password!

Especially if you have fiber optics, call your isp and ask them to check your connection. Give them all the specifics about your router. Also, I'm not familiar with that specific router, but sometimes it helps to update the router's firmware. Also, the router itself may be faulty. Could even be some sort of loose connection. The isp should ask you to reset the router by unplugging for 10 secs and plugging it back in.

Is there any reason why you are not taking the Free upgrade to W10? it's awesome and Free until July 29th this yr.

Firmware for router has been installed 3 months ago. Router and signal tested last week by service provider. I have never had to use a password to get online and do not have a guest network. Win10 was installed last Aug. and removed 8 days later. The computer was nearly unusable for me and my hubby also started to have problems opening mail, facebook, calendar and using Cortana. I am second user signed in to this computer, I used Cortana for 4 days and it quit completely, I could not open my mail and was forced to use online mailbox of service provider. My calendar would not open nor would people app for email addresses. After all that, I read the same complaints from over 400 people on M$ site with no clear fixes. I tried 2 of them, spent over 2 1/2 hours on phone with tech help. Then I removed the Win10. I have read that there is an update to "supposedly" fix those issues. I would like to be able to rely on my internet connection before reinstalling Win10.

I would be most grateful if I had some places to check to find out how to solve the connections. My router is plugged into cpu by Ethernet cable. I open the pc settings and enable the wifi. Later, I will see on my phone or computer screen that wifi has been lost. The wifi seems to "connect" and "disconnect" at will. I have no idea why this is. I will be on a web page and use a link to read an article when I get the page that reads, "this page cannot be displayed". I then click on "fix connection problems" which brings up Windows Network Diagnostics. It may "reset the Ethernet adapter" and I close the page, and the page I had clicked the link for comes up. It may happen again right away, then resets the Ethernet adapter once again. Or network diagnostics may say the "Ethernet does not have valid IP address". I cannot find where that is. Even if I did, I have no idea what information I would need to know to make the correct change. Tia

My router is plugged into cpu by Ethernet cable (emphasis added). I open the pc settings
and enable the wifi. Later, I will see on my phone or computer screen
that wifi has been lost. The wifi seems to "connect" and "disconnect" at
will.

Maybe it's a typo or a terminology error but typically one would use either a Ethernet or WiFI connection, not both. Usually...

Modem ==> Router ==> Computer or Modem/Router ==> Computer

The connection from the router can be via Ethernet cable or WiFi.

If you are using both, that might account for the problems you are having.

I had a similar problem. One of these sites might help.

Reset Winsock in Windows 10 / 8 / 7

http://forum.thewindowsclub.com/windows-tips-tutorials-articles/35087-reset-winsock-windows-10-8-7-a.html

Network & Internet connection problems in Windows 10/8/7

http://www.thewindowsclub.com/how-to-fix-network-internet-connection-problems-in-windows

Clear, Reset, Flush Windows DNS Cache

http://www.thewindowsclub.com/flush-windows-dns-cache#comment-27570

Reset TCP/IP or Internet Protocol in Windows 10 / 8 / 7

http://www.thewindowsclub.com/reset-tcp-ip-internet-protocol

Really just sounds like your Router or Modem is Dropping the connection. Unplugging either the Router or the Modem may temporarily take care of this problem.

I would first try unplugging the Power Cable from the Router for 10-30 seconds then plug it back in. See if this takes care of the problem and if it does, how long between episodes (next time it happens)?

You can also try the same with the Modem, but don't do both at the same time or you may never figure out which is causing the problem (try the Router for one week, then try the modem the next week).