I shouldn't run a speedtest while doing a download. They compete for the available bandwidth (and, seeing the message, maybe other resources).
The first thing to do is to determine if this is an issue of your PC or the connection (router, modem, cabl- or phone line, ISP). Ask a friend with a laptop to come and try.
If it's your PC, then maybe "the newest drivers" are a problem. What drivers, where did they come from and what made you install them (what was wrong with the old ones)? Anyway, try a system restore back to before this issue turned up.
If it's not your PC (so if it happens on your friends laptop also) reset the router and the modem and see if that helps.
So I've noticed a few days ago that I can't download anything from internet browsers. The download starts, it downloads like 10-20 MB and then the download speed drops to 0. After some time, it says Download Failed- Network Error. I'm on Ethernet and have the newest drivers installed. I deep scanned my pc for viruses, I don't have any. I've tried to speedtest when I'm not downloading something, and then it's fine, but when I speedtest while I'm downloading something, the download speed jumps to 650 and I get the message: "A socket error occurred during the download test. A firewall could be blocking the connection or the server might be having some issues. Please try again later." I've tried disabling my Avast web shield and it still doesn't work. Does anyone know how to fix this? I can also browse the internet with no problem, it's just the downloads that are the problem.