Windows 10 Slow Network Performance After Updating

Unfortunately, when I did a reinstall earlier this week, the installer downloaded the updates while starting the install and didn't allow me to say no, so there is no way to rollback the patches because in Microsoft's infinite wisdom, it decided not to do what it has always done and install the base version then update from there.

Sadly, my only recourse (which I don't want to do at this point) would be to clean reinstall 20H2 AGAIN (this would be the fourth time) with the internet disconnected, then when activated and all of my applications are reinstalled (an hours-long process), create a system restore point, and start installing updates one at a time. I don't have the time or energy to do that. If I have to troubleshoot this stuff for Microsoft, maybe I'll just switch to Linux. It really makes me wonder why I got suckered into paying a license for a broken OS.

A Reset removes all System Restore Points. Make sure System Restore is turned on and set a Restore Point first.

System Restore your first line of defense if Windows ever malfunctions as it can run even from recovery media to get you back before a problem started. It should always be turned on C drive with plenty of disk space (5-15%) configured. Here's how to check and when necessary how to run System Restore: https://www.windowscentral.com/how-use-system-r...

One thing that should survive Reset is Device manager > Device > Driver tab > Update Drivers > Browse > Let Me Pick to see all previously installed drivers.

It's possible some of the network devices and settings you turned off may be causing this. I'd turn them back on to see. These changes often cause unintended consequences, like any modifications or most registry edits.

I know you don't want to reinstall, but I still need to ask since it is what has worked for millions of others and not one ever came back with further problems I've seen: When was the last Clean Install like the gold standard Clean Install in this link which compiles the best possible Install of Windows which will stay that way as long as you stick with the tools and methods given, has zero reported problems, and is better than any amount of money could buy: http://answers.microsoft.com/en-us/windows/wiki... ?

It is also a great learning experience that will make you permanently the master of your PC''s because you will learn what works best and how to apply it with your own hands.

Hi Moose. I'm Greg, awarded MVP for eleven years, Volunteer Moderator, and Independent Advisor here to help you until this is resolved.

1. See if you can System Restore to a point before the problem started:

https://www.windowscentral.com/how-use-system-r...

System Restore is your first line of defense and can take you back to a point before a problem began. If it doesn't help then you can undo it. Read about it first in the tutorial above and then try restoring to just before this started.

If the problem repeats or System Restore doesn't work then check which Windows Updates were installed at Settings > Update & Security > Windows Updates > Update History, uninstall them there or System Restore again, then immediately check for and block the Updates with the Hide Updates tool explained here: https://www.tenforums.com/tutorials/8280-hide-s...

2. If this was caused by a Version Update then for 10 days you can roll it back in Settings>Update & Security>Recovery and then hide it until it matures using the Hide Updates Tool which is explained more here:

https://www.tenforums.com/tutorials/8280-hide-s...

3. See fixes for slow downloads in Windows 10:

https://helpdeskgeek.com/windows-10/how-to-get-...

https://techcommunity.microsoft.com/t5/windows-...

https://www.majorgeeks.com/content/page/how_to_...

https://www.drivethelife.com/windows-10/fix-slo...

https://www.youtube.com/watch?v=nF6XFrYMOd8

4. Update your network adapter drivers from the PC maker's Support Downloads web page using the full model number, HP Serial Number or Dell Service Tag on sticker. Compare the latest drivers available for download with the ones presently installed in Device Manager reached by right clicking the Start Menu. Make sure you have the latest BIOS or UEFI firmware, Chipset, Display (Video), Sound, USB3, Bluetooth, Network and all other drivers, or else download and install the latest now.

If you have the latest network driver then try on it's Driver tab also to Roll Back, or Uninstall and then restart PC to reinstall the driver. Try also all older drivers from Update Driver > Browse > Let Me Pick list working backwards.

Go to Device Manager > Network Adapters, select Wifi adapter, then Power Management tab, clear the check box to "Allow the computer to turn off the device to save energy." Then on the Advanced tab disable any energy-saving options.

Enable IPv6 in the network adapter settings:

https://www.translatetheweb.com/?ref=TVert&...

Run the fixit from https://support.microsoft.com/help/929852 (Re-enable IPv6 on all nontunnel interfaces) and reboot.

Right click the network icon in System Tray at bottom right end of task bar to Troubleshoot Problems.

Try all of these steps:

Fix network connection issues in Windows - Windows Help https://www.translatetheweb.com/?ref=TVert&...

Go to Settings > Network & Internet > WIfi > Manage Known Networks, highlight and remove the network having problems, restart PC to see if it shows up again.

Try plugging in by ethernet cable to the router to compare, then plug the ethernet cable into the modem (if separate) to see if this might be an issue with the router.

Try powering off modem, router and PC and then restarting in that order with 1 minute in between each. You may need to reset your router or even optimize it following these steps:

https://www.translatetheweb.com/?ref=TVert&...

https://translate.google.com/translate?sl=auto&...

Your router manual is always available from the manufacturer's website for your exact model.

You also are entitled to Support from your internet provider to get online on all devices. This is always included in the monthly bill. If your router is less than a year old they will also Support getting it connected and optimized.

Another option is you could replace the wireless adapter with an inexpensive USB nano adapter like this one:

https://www.amazon.com/OURLiNK-600Mbps-Wireless...

If nothing else works then do a Repair Install, by installing Media Creation Tool, open tool and choose to Upgrade Now. This reinstalls Windows while keeping files, programs and most settings in place, is the most stable method to advance to the latest version, and solves most problems. http://windows.microsoft.com/en-us/windows-10/m...

I hope this helps. Feel free to ask back any questions and keep me posted. If you will wait to choose if I resolved your problem, I will keep working with you until it's resolved.

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Standard Disclaimer: There are links to non-Microsoft websites. The pages appear to be providing accurate, safe information. Watch out for ads on the sites that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the sites before you decide to download and install it.

I'm well aware that a reset removes system restore points. What I'm saying is that when I did the reset to 2004, it fixed it until I ran Windows Update. The problem is that post reset and update, Windows didn't set valid restore points prior to the updates.

Well, I've been able to narrow it down at least a little bit. I performed a reset install with the latest Win 10 media and the 2004 media that I had. Win 10 2004 without updates on the same system and the exact same drivers behaves normally in all cases. However, with Win 10 20H2 and the latest updates with the same drivers and default config in the case of Win 10 2004 shows the slowdown when specific applications are open. When they are closed I get the full bandwidth that my ISP can supply.

It seems like the updates from mid-march (I still haven't been able to narrow down which one) don't like something that applications like the Second Life viewer and Firestorm are doing, and triggers the bandwidth limit. I have my server running 20H2 without the latest updates, and my plan is to step through them one at a time to see which update triggers the behavior. There may be other applications that trigger the behavior, but the one I've been able to most reliably replicate it with has been Second Life and Firestorm.

All of these tweaks and settings changes really shouldn't matter if everything worked properly with default settings before applying updates and the system is running fine in the default state with the application running prior to updating. Doing a quick Google search, I'm coming up with more and more posts like mine where people are complaining about slow network performance in similar situations, so that tells me the likely common culprit here is either a bad update shipped by Microsoft, or a bug fix that other software vendors were relying on that is now causing unexpected bandwidth limitations.

For #1 and #2 because I performed a system reset (which I don't want to do again because I'll have to reinstall EVERYTHING including downloading several hundred GB with my local internet monopoly's abusive usage caps), I have no restore points to fall back on. There's clearly something with one of the updates released in the last month or so that's borked, and it impacts both version 2004 and 20H2.

For #3 the majority of the articles talk about WiFi. This is impacting this specific computer with both 802.11AX WiFi AND wired gigabit. It also behaved the same way with a similar image on my prior B450-based motherboard. I have gigabit down, and while every other machine that isn't updated is seeing the speeds, this specific machine is not when it is up to date. I'm reticent to update my other computers (especially my work laptop) because of this issue. Drivers are up to date, and I've already followed all of the suggestions on Majorhardware and the other sites that you linked including what's in the YouTube video that you link.

For #4 since I built this machine myself, I don't have a "PC maker" to go to. However, I am using the latest drivers for everything that are supplied by my motherboard vendor and were working JUST FINE before I started updating windows after the last reinstall. Unfortunately, Windows decided not to checkpoint any of the updates, so I don't have a way of rolling them back. I suspect it might have something to do with the "Servicing Stack 10.0.19041.903" update since that is the only one that I couldn't roll back of the 3 that were showing last night.

I've also tried older drivers for both WiFi and my Ethernet controller with no luck. IPv6 is fully enabled and I'm able to connect externally with it. The "Fix network connection issues" tool built in to Windows doesn't find anything wrong since it only checks for basic connectivity and doesn't test throughput. Additionally, since this is my gaming desktop, I have all power saving features disabled, including turning off network devices (whether wired or wireless).

And I get the same result whether I use my new AX router via WiFi or wired, my old AC1900 router via WiFi or wired, and wired directly to my cable modem. None of my other Win 10 systems (again, because they aren't fully updated), Android devices, or network appliances have this issue and can download at or very near the full 950Mb/s to 980Mb/s that my cable connection can provide. I have to reiterate that this issue is localized to a single machine on my network, since a dozen or more devices running various operating systems are NOT having this issue. This occurred on the same install of Windows on two different motherboard/CPU combinations (one ASUS TUF B450M-Plus GAMING and the other ASUS TUF X570 Pro +WiFi). 

Incidentally, if I boot into another operating system, such as a Live Linux OS, I don't have ANY issues with my gaming desktop like I have in Windows after updating fully even after performing a Repair install as I had initially mentioned.