Sudden (within last couple days) network/internet connection issues on my PC

I’ve just recently noticed weird glitches when connecting to the internet with my main work PC, which is less than a year old and normally very speedy in all functions. Sometimes when I open a web page, I get a “page not found” error for a couple seconds before it loads, or the page comes up, but the images fail to load immediately. Sometimes the images don’t load at all until I hit refresh.

Worst of all, I’m having big problems logging into a CMS I manage for work. When I enter my credentials it will often say “page not found”. I was on the phone with tech support for the CMS yesterday and they said there was no issue on their end. I eventually found that if I refresh the page several times after I log in, the page will eventually come up, but then I continue to have issues navigating through the CMS.

Here are things I’ve checked or fixes I’ve attempted:

  • Speedtest.net says 120 Mbps down, 12Mbps up.
  • Confirmed the issue occurred in several browsers, not just the main one I use the CMS in.
  • Problem does not appear to happen when logging in on another device, so apparently not my network or internet connection.
  • I tried flushing my DNS cache, which initially seemed to fix the issue, but it returned.
  • Did a malware scan, which found nothing.
  • I did have a couple recent PC updates which seem to correspond with the onset of the issue. Should I try to roll back one or both of these?

2022-04 Cumulative Update for Windows 10 Version 21H2 for x64-based Systems (KB5012599)
Successfully installed on 4/18/2022

2022-04 Cumulative Update for .NET Framework 3.5 and 4.8 for Windows 10 Version for x64 (KB5012117)
Successfully installed on 4/17/2022

Have you tried rebooting? As a matter of fact, my bluetooth mouse stopped working while I was reading your post. I rebooted and it is back.

Yes, forgot to mention it, but rebooting was the very first thing I tried. As with flushing the DNS cache, it seemed to work at first but the problem soon returned.

I’m noticing the issue with a lot of websites I try to visit now. I get a “page not found” error, which either resolves by itself in a couple seconds, or gets stuck that way until I do a refresh or two, and the page will finally load. It’s something I can work around for now but it’s very annoying.

I know you said it seems isolated to the particular device but do reboot all your network stuff anyway.
Also, when it’s especially bad, try disabling wifi from the system tray, wait a few moments, enable again to see if it improves.

First @solost, thanks for the detailed description of your problem and the steps you have already taken, we IT folks appreciate this because it’s not the norm for this kind of advice seeking threads. So when I read the thread title and the first sentence of the OP, my inner voice immediately said “It’s a DNS issue.” My advice would have been to flush the DNS on the machine and to power-cycle the router. But then you said that you’ve already did the flush and that the other devices on the network don’t have that problem, so a DNS issue now seems unlikely to me. But if you haven’t done already, power-cycling the router still could be worth a try.

I’m glad you posted this because something similar happened to me. It was on my home desktop using Chrome. For two days (Tuesday and Wednesday) every time I visited a site for the first time, it didn’t load properly. Sorry, I’m not as good as explaining this as you are. What I would see was the information for the site scrolling down the left side of the page with bits of code and squares where images would be. Refresh wouldn’t fix it but if I shut down the page and then reopened it, the site would be fine.

I ran a scan but found nothing. I didn’t think to check other browsers. I reboot the system every day. I almost started a thread about it but just figured that it was my computer since it’s 8 or 9 years old. I started looking at buying a new one. But today everything is back to normal.

Yup. I would definitely give this a go.
It is clearly something in the DNS chain given both rebooting and clearing the cache help.
Also be sure what your computer is using as its DNS server. A common debugging trick is to force it to use Google’s at 8.8.8.8 as a known good service.
It isn’t impossible your computer is defaulting or falling back to a different DNS service from its initial setting. I would assume it should be using DHCP to find it. But being a work computer some setup may be different.

I second this.

They also use 8.8.4.4

If you are using a wireless connection try a wired connection.

Or, if using wireless, turn off your wireless router and use your phone as a hotspot to test (not for long if you have limited data on your phone but fine for a quick check).

Thanks for the replies! I haven’t actually power-cycled the router yet due to extenuating circumstances (the router is in a closet in a room where my wife fosters mom cats with kittens too young to adopt, and this latest mom cat does not like me, and tends to attack me when I enter the room. She seems to like my wife better, so I’d prefer to enter with my wife, but she’s about out the door for work).

I mean, I would definitely power-cycle the router if I thought the router was really the issue, mean cat or not, but I’ve now tried two alternate devices (both Mac laptops on a wireless connection) and no issues whatsoever. My work PC has a wired connection but it also has wireless, so I tried unplugging the cat5 cable and running wirelessly on the PC-- same issue, just slower.

It seems isolated to my PC. Does nobody think that the April Win10 updates I mentioned upthread may be the culprit? I know correlation does not necessarily equal causation, but it seems awfully suspicious that this is happening after the updates a few days ago. I’m tempted to roll them back, but it’s shaping up to be a busy day, and as annoying as it is to constantly refresh the browser half a dozen times, I don’t want to risk temporarily bricking my PC with a rollback attempt gone bad and spend half the day doing repair / restoration. May have to wait for the weekend.

I don’t know how to do this. Can I get a “for dummies” explanation? :blush:

That was my first thought: maybe your wireless network adapter is glitching. Have you tried troubleshooting the network using the built-in MS troubleshooter ?

At the moment when this is happening, do you still appear to have connectivity (via the WiFi icon on your taskbar) ?

ETA: this makes my idea pretty unlikely, but worth a check, and maybe useful for somebody down the road.

You could flip the circuit breaker for that room and reset it.

More than one way to skin a cat. :wink:

Yes, that is an option, and it’s not that big a deal to go into the room, I just don’t want to freak out the mom cat too much. But it’s not so much needing to figure out a way to reset the router as, I really don’t think it’s the router, since I’ve tested with two separate Mac laptops on the same network and they have no problem whatsoever. I really think it’s an issue with my PC.

So, just to follow up, over the weekend I uninstalled Windows security update KB5012599 and that seems to have fixed the problem.

scratch that-- the problem seemed to have gone away, but now it’s back :rage:

Did you get that router reset yet? Honestly, I’d stop trying anything until you do.

Yes, I reset the router as well.

Have you turned off every background program that you can?

Done a CTRL+ALT+DEL and checked the Task Manager Performance and Processes tabs? On performance you can check the data going out.

At a stretch, are your temps ok? Overheating can cause the PC to throttle performance to save itself.

Sorry, been a busy week, and since I figured out I can get sites to work by refreshing the page a few times, it’s gone from a critical problem to a very aggravating but workaroundable annoyance. But I still want to fix it.

Anyway, RE: background programs: I’ve looked through Task Manager, don’t see anything clearly amiss, and I tried turning off a few background programs, but I’m not really sure which ones I can safely stop. How do I know I’m not causing a different network connection issue by turning off the wrong program?

The temps are perfectly within range at all times.

Some more info:

Almost any website I visit for the first time, I get the message “We can’t connect to the server at [URL].” One or two page refreshes will bring the site up. If it’s a site I’ve visited at least once before, it comes up fine. Which seems to point to a DNS issue, but I already tried a DNS flush.

Sometimes the page will come up, but unstyled, so the stylesheet is somehow blocked-- until I refresh the page once or twice.

I mentioned the CMS I manage for work is a big issue-- I have to refresh the page several times to get a page to come up within the CMS.

But also, when I push code to the CMS from a code editor I’m getting errors at first, and it takes me 3 or 4 push attempts for it to finally work. So uploads seem to be an issue as well as downloads. FTP connections take a few tries as well.

Did you ever get instructions on how to change your DNS server? Here’s the simplest guide I found:

Brilliant, I switched to the Google DNS and everything seems to be loading flawlessy! Thanks a lot for those instructions, @BigT .

Now, going forward, I’m wondering, can and should I leave it set to the DNS server? According to @Francis_Vaughan , it’s a good ‘debugging trick’, which seems to mean something to test but not use permanently. Is there any downside to always using the Google DNS from now on, other than the fact that Google will presumably be able to track any site I visit from this machine, from any browser, whether I’m logged into my Google account or not?