Windows 10: Internet Fails under any usage, reconnects when idle

The current problem that I am having is that the wireless connection on my desktop will fail once I try using it ie. loading a webpage or running a speed test. The problem has just happened, and the only change is that we recently moved from our own modem and router which was apparently dying over to the Xfinity xFi modem/router. With the change over, we have multiple different devices that connect to our wireless and one on ethernet. 2 smartphones, 1 Macintosh laptop, and 1 Windows 10 Desktop with onboard wi-fi. We also have 1 game console that connects via ethernet directly to the xFi modem. prior to the change over, and the reason for the change to the xFi modem, all devices were running speed tests of about 6/1 MB/s on a plan that we should be receiving 600/20 MB/s. This was the same for all devices on the wifi including the Windows 10 PC, where as the ethernet gaming console was getting about 200/15 on the wired connection. After switching over to the xFi router, the speed for each devices were as follows:


Game Console : 320/18

Macbook : 460/11

2 Smartphones : ~215/17

Windows 10 PC : failed to connect for test


The internet on the PC would show as connected, as soon as the speed test was initiated ookla SpeedTest for desktop the internet would disconnect.


The following troubleshoots were tried:

Resetting the PC

Resetting the modem

Changing the SSID and password of the WiFi network

Uninstalling/reinstalling Wi-Fi network adapter

Updating the driver to the latest version

ipconfig/flushdns via administrative command prompt

ipconfig/release via administrative command prompt

ipconfig/renew via administrative command prompt

netsh winsock reset via administrative command prompt

netsh int ip reset via administrative command prompt

Changed from dynamic DNS to Google Public DNS via Wi-Fi properties for both IPv4 and IPv6 protocols

Deselected "Register this connection's addresses in DNS" via both IPv4/IPv6 Advanced TPC/IP Settings


As of this point I'm at a loss. The most recent change was the last one, and after that, I was able to get a webpage to load youtube.com and was able to complete my first of 2 speed tests. The first test primarily ran at about .09 MB/s download until the last second it shot up to 20 MB/s and gave me final numbers of 20/10. The second test which I conducted seconds later, never spiked and instead returned results of .09/15. I tried running a 3rd test and the SpeedTest app disconnected from the internet, but my notifications still suggest I have internet.


While normally I would be on the bandwagon of this is comcasts fault, the fact that everything else in the home is working flawlessley on the new xFi modem would lead me to suggest that this is very specific to the Windows 10 PC. But the fact that this same PC was working as good or better than any other device in the home prior to the change over of modems, leads me to believe that its more of a file corruption than it is a hardware issue.


Just incase its relevant, below are what I believe would be the pertinent computer components:

Windows 10 Pro build 19041.388

MSI B450 GAMING PRO CARBON AC motherboard with Intel Wireless-AC 9260 160MHz network adapter


Does anyone know of any other changes that I could try to do in order to get this to work again?


Thank you in advance.

:)

 

How fix 4-times-higher CPU usage at idle?

Yes, I have noticed negative effects on my PC's performance:

-Browsing is slower when I open multiple tabs rapidly. I do this a lot (I research multiple links in online articles).

-My PC gets much hotter, and stays hot--so much hotter that I have to turn it off.

After the Windows 10 Anniversary Update, the 39% CPU usage screen shot of my Process Manager was when I was doing nothing--no browsing, word processing, etc. Before I took the screen shots, I closed all application programs. My machine was leveled out, as you better describe it (the screen shots were taken 5 minutes after my PC first leveled out). My PC is 39% CPU usage when leveled out; never lower.

Before the Windows 10 Anniversary Update, my PC was 10% CPU usage when it leveled out. And it stayed there.

1 other PC we have with the Windows 10 Anniversary Update (same model as my PC) *HAS* the 39%-CPU-usage-at-idle problem.

2 other PCs we have with the Windows 10 Anniversary Update (different brands) DO *NOT* HAVE the 39%-CPU-usage-at-idle problem. They have only 10% CPU usage at idle.

[NOTE I've no software to my PC after the Anniversary Update. My programs, etc. the are same as before.]

Any ideas on what to do to fix my high CPU usage?:
-use Process Explorer? (how do I use it in this case?)
-reinstall hardware drivers? (which ones?)
-suspend certain services? (which ones?)

I've seen comments suggesting each of the above ideas. I need step-by-step instructions (ideally screen shots) for Process Explorer. For drivers & services, which do I try?

Any ideas on the above possible fixes OR better fixes for my high-CPU-at-idle problem? I'd really appreciate them

 

Constant 100% Disk Usage, 60-80% CPU usage. Both happen when idle.

Could you also provide a snapshot of Resource Monitor with selected Disk Activity Tab and checked only System:

i would also suggest running checkdisk and sfc /scannow

 

How fix 4-times-higher CPU usage at idle?

This is good to know. Thank you.

OK, now I know that the problem is affecting the two Dell XPS 12s you have, whereas the other two computers you listed are not having them, this will help me in diagnosing the problem by narrowing it down.

After querying the search engines with your particular device specifications and the problem, the first thing I want you to try is deleting any ghost devices in Device Manager. "Ghost devices" can hog system resources and will be greyed out in Device Manager while doing absolutely nothing, and there is no harm in deleting any of them as long as they are greyed out, like this:



Though this window is for an older Windows installation, yours will be no different, except for the devices listed. Any ghost devices will be grey. In order to see ghost devices in the first place, follow this snippet from Microsoft tech support that I found on Microsoft's help forums:

After you have done this, proceed with the following instructions:

After performing these instructions, let me know what your Task Manager is reporting. Or if it didn't work, let me know and I'll dig a little deeper into the problem.

EDIT:
Make sure when uninstalling ghost devices that you check each dependency tree, like Monitors, Network adapters, Portable Devices, Printers, System Devices, etc. Just make sure you check every tree for greyed out devices. Also, the reason I chose this method of potential fix is because it's not uncommon for ghost devices to cause high CPU, especially since in your Task Manager, the highest CPU using Process is "System" when at idle. Seeing as how none of your other programs are requesting high amounts of CPU usage, this also tells me it's not anything you installed, rather the system itself is busily working on something in the background.

Also, after completing everything listed above, in Task Manager scroll through the Startup tab, right click and disable anything that isn't vital or needed. like software updaters. Keep only bare necessities like sound processes or antivirus handlers. Then finally, restart one more time.