HELP PLEASE

[LethaR]

I have a 600mb/s wired network (don't sure if it's said like that, i'm spanish, sorry) but i'm only getting around 100mb/s. The problem goes further that than, because if it was only that, i could call my wifi company to help me. The problem comes when every device in my house, including my laptop, does get those 600mb/s but my main pc, the desktop one, is the one that gets only around 100. Not only so, but it gets even worse when trying to download anything, even with 100mb/s it obviously has to be fast enough to download everything in minutes, but trying to download 200mb applications it lasts for hours, sometimes it gives me a network error and doesn't finish downloading, trying to update a game lasts for hours, with an average of 500kb-1mb/s. Other thing i noticed is that if i go to task manager and click in my main hard drive, the one where i have my windows 10 installed, it says it's constantly reading and writing, even when im doing literally nothing on my desktop, don't even know if that's normal but i'm going to highlight it anyways... 

So, i'm not really sure of anything that is happening to my pc, don't know if it's a virus, some kind of problem with the components, or what is really happening. I really need help.

[RONOTHAN##]

What are the specs of the computer, that will help a ton with figuring out what's wrong. For example, all of this can be explained by having a really old computer with a pentium and a 100mbps network card, and since most games come compressed, the pentium would be decompressing it at extremely slow speeds

[LethaR]

you can see my specs in my profile, but that you're saying is not my case, i have a pretty high end pc, with a i7 9700k, 32gb 3200mhz ram and a brand new rtx 3080, with 2 ssd's and a m.2 nvme drive. That's why i'm that worried.

[Hairless Monkey]

2 minutes ago, LethaR said:

you can see my specs in my profile, but that you're saying is not my case, i have a pretty high end pc, with a i7 9700k, 32gb 3200mhz ram and a brand new rtx 3080, with 2 ssd's and a m.2 nvme drive. That's why i'm that worried.

What does the constant usage on the Disk look like? 1% usage, 100% usage? If the latter, this could very well be the route of the problem. Can you provide a screenshot of your task manager sorted by disk usage?