Progressively Slower Internet Despite Many Attempts to Resolveth Issue

I am having currenly insoluble problems with slow internet on Windows 10. My computer is fine when not using a browser. These problems extend back several months during which time I have struggled to solve the problem by reading everything I can find on the the subject on the various forums etc. Nothing has made any significant difference to the slow, choppy and sometimes unuseable internet service. The problem has extended through numerous Windows updates, both minor and major.

To give some idea of the scale of the problem, I often use the home page of the Daily mail as a test because it is huge. When my internet is performing at its best, this page downloads in about 30 seconds. However, as time goes on it quickly reaches the sateg where the page download never completes - the browser just seems to come to a grinding halt. Although I normally use Firefox, I have done extensive comparisons with MS Edge, Chrome etc. There is no aprreciable differnce between browsers.

My PC is connected using a wired Ethernet connection although I have tried switching to Wireless - only to see more or less the same slow performance.

I have tried:
switching off P2P
limiting the bandwidth available to Windows for updates
quitting all background apps
suspending all non-Microsoft services
disabling Windows updates (temporarily)
updating all drivers (except the watchdog timer which I cannot figure out as it does not appear in my apps list)
using CCleaner to clear debris and resolve all registry errors
uninstalling OneNote
disabling Windows 10 auto-tuning
disabling Large Send Offload
disabling all firewalls and virus protection (temporarily),
doing extensive and thorough scans for malware etc

There are probably also other things I have tried but have forgotten to list.

There is, as far as I can see, only one glimmer of hope. I have noted that, after a Windows update completes, the internet is as fast as one would expect with a 7MB line (I live in a rural area which will be the last to benefit from faster speeds). However, even this is not 100% true - most Windows updates have produced an improvement in speed, but a few have not made any difference. When an improvement is seen, this lasts for only a few hours as the internet becomes slower and slower once again. A similar, uncertain diagnosis is apparent with regard to rebooting the PC. Sometimes a temporary improvement is experienced, but sometimes no difference is seen.
I have not tried reloading Windows because the performance of the PC is fine for all non-internet apps. For instance, I work a lot with Photoshop which is a large and complex program, but there are no speed issues at all - everything is fine.

There must be a logical explanation for the behaviour I am experiencing but I cannot yet pin it down in a more precise manner. Does anyone have any ideas?

Thank you very much for your reply. I appreciate your help.

Uninstalling all AV made no perceptible difference. I do not have any performance/3rd party cleaners installed other than CCleaner. Uninstalling this made no difference.

I ran all four commands that you kindly explained. nbtstat-RR came back with a message "not recognised as an internal or external command", but the other three ran successfully. I then restarted the PC.

The immediate consequence is that the internet is running very fast - ie given the limitations of my 7Mb connection. The Daily Mail home page, that I often use as a sort of "reference webpage load", loaded in less than 10 seconds. That is as good as I would expect ever to get. So, good news - BUT the history of this problem is that, in the case of all solutions I have previously tried, the slow performance creeps back over a few hours of use. Please forgive me, therefore, if I reserve judgement for a while. I have to wait and see what happens in the next 24/48 hours.

I do maintain boot media but would have to recreate it because Windows has been updated in the last few days.

I will post again once it becomes clear whether or not slow performance is returning.

Thank you

Thanks again.

I discovered that if I use the command "nbtstat - RR" I get a result (- which I do not understand). Note that I used a space on either side of the RR characters. The result is captured in the attached image.

Incidentally, the faster speed remains for the time being!

OK, the slow speed returned gradually. It seems that the more I download, the more the internet speed slows. Yesterday, the speed had reduced quite a bit but the internet was still useable. I then did a large download - 3GB, which proceeded normally - and after that the internet browser was unuseable. The browser tried to download but progress on anything but the smallest pages just came to a halt.

Having restarted the PC, the speed is back up to its fastest, so I am still not in a position to try the commands that you suggested one at a time. I will do that when the problem returns but it is a slow fault-finding process. Every time I get good speeds, I have to wait another 24/48 hours before it slows once again.

Hi folks

1) Try clearing DNS cache
2) try switching DNS to public GOOGLE ones (usually a load faster than standard ISP ones)

public google dns servers here

https://developers.google.com/speed/public-dns/

3) check if IPV6 is active / auto translate -- that might be in your modem set up.
4) Restart every device using net including smart TV's, tablets, phones etc.

If all that lot fails to clear the problem change provider if poss.

Note some providers cap speeds if downloads are near monthly limit or load of people using the service at the same time. Netflix etc are very popular all over the place so a lot more people are streaming Hi res video now -- lot of bandwidth needed for that type of service.

Cheers
jimbo

Once again, thanks for all the replies - the help is appreciated.

Having said earlier that the slow internet speed slowly crept back into being, the characteristics of the problem do seem to have changed since executing the four commands mentioned in Caledon Ken's first reply. Now, it seems, that the faster "normal" speed returns every time the PC is restarted - which was not always the case previously. That is at least some progress.

I note the comments by jimbo45, and have checked and foundd that ip6 is not active. I have also tried restarting every connected device without much evidence of any change in the situation. Please understand that the nature of the problem makes black and white yes/no answers difficult to obtain. I always have to wait a while to see whether the internet speed remains OK or slows down once again.

With regard to providers slowing downloads when nearing monthly limits, that is not supposed to be the case here. I am with BT and the deal is "unlimited" - so I guess if that is happening it would be unlikely to be admitted. However, I worked today for a short period on the internet and the speed remained OK. I then did masses of image processing using Photoshop over a period of several hours. When I returned to the internet the speed was appallingly slow - almost unuseable. I therefore restarted the PC and the download speed returned to normal. Can the heavy off-line processing affect anything to do with internet speed? It would have to be something that is cleared by restarting the PC.

I am sorry that this is all so grey and laced with "ifs" and "buts", but it seems almost impossible to nail down any specific fault characteristic. Everthing I try necessitaes another 24 hour wait to see what happens - I drives me mad!

Thanks to all.