Very bizarre internet problems - Hardware & Software

I've been having some very bizarre internet problems for the last week or so. It started with the internet going really slow. I was getting 0.3 Mb/s down and about 12Mb/s up on a 50/15 Mb/s connection. Since I had 45GB of downloads on my phone I just assumed this was a temporary fault and started tethering my phone. The problem continued to persist but seeing as I still had tonnes of downloads left and I had zero interest in getting the runaround from the ISP I kept using it. Today though just on a whim I ran a speedtest on my phone connected to the home internet and got 35/14 Mb/s which is about what I was getting before the problems started. I double checked I wasn't connected to the mobile internet and ran the test again to get the same result. I then ran the test on my computer through the wireless card and got 0.3 Mb/s down. I then tethered my phone and using the home wireless I got 0.3 Mb/s down. Switching my phone to mobile internet I did the speedtest again and got about 12 Mb/s down. So (for once) the issue isn't my ISP. I have no clue really where to start figuring this out. Any ideas? Summary: Wireless on PC through wireless card - 0.3 Mb/s down Wireless on phone - 35 Mb/s down Wireless on PC through phone - 0.3 Mb/s down Mobile internet on PC through phone - 12 Mb/s

Sounds like your machine is being specifically throttled. Maybe your ISP is doing it because they've detected "suspicious" traffic or torrent downloads? I would contact them. Something similar happened to a friend of mine, and they specifically throttled his machine on the network. They didn't in any way notify him of this until he called.

My ISP has zero power to throttle a single computer on my side of my router.

So it's not an ISP-provided router? Well then I don't know.

Just ran another experiment. Steam is downloading at about 5 Mb/s and peaking at about 10 Mb/s. That's poorer than usual but far better than I'm getting in speedtests. Perhaps its just web browsers being throttled?

Have you changed your power options so that Wireless Adapter is on Maximum Performance rather than Power Saving? A couple of things I found helped with giving me a stable speed was setting my adapter to a static IP and changing my DNS servers to 1.1.1.1 and 1.0.0.1. Additionally, checking the Power Management tab of each of your USB interfaces and wifi adapter in Device Manager could help alleviate the problem. Try these and see how you get on?

It's not a wireless issue which should be obvious given the wireless works fine on other devices.

Not necessarily - the wifi may not be a problem but your device's configuration could be. Did you try unchecking the Power Management option in Device Manager as suggested?

Is the OP unclear to you? Do you not understand the idea that the internet speed is perfectly fine on my phone but it suddenly stops working when plugged into my computer? Or the idea that my computer does not have control over my phone's power management settings?

The OP is clear to me, I was just trying to be helpful and offer suggestions for what you could do. I had a very similar problem a few weeks ago and what I said in my post solved the problem for me. Good luck with solving your problem.