[SOLVED] What is wrong with my PC?

[Diabetes]

So I have a gigabit connection. The setup is: ISP modem (DIGI (isp) oem Huawei, can't remember the exact model) that goes to an Archer C2 AC750 router. All 4 LAN ports are used on the router. I'm using CAT5e cables. On my laptop, I get the full speed, and have no problems with the connection, no matter the port on the router. But my other PC is only pulling 500-600 mbps at max in Speedtest. (Tested because downloads felt slower on that PC) The PC has an Asrock Ab350m-HDV motherboard. I tested the cable with my laptop, and it was pulling around 950 mbps as it should. Plug it back to the PC, now it's only pulling 200 mbps. I reinstalled all LAN drivers, checked the windows settings, cleaned the port with compressed air, but I couldn't find a clue why the internet is so slow. In control panel, under adapter settings the speed is 1 Gbps. Using task manager, there was nothing else using the internet when I tested it. Is there something I missed?

 

[COLGeek]

Are the Realtek network drivers up to date (most current version)? Same question for your motherboard BIOS.

 

[SamirD]

Check the cable and try re-seating it several times, especially if it varies in speed each time as it is making a marginal connection.

 

[Diabetes]

All drivers and BIOS are up to date. Re-seated the cable, and still the same. The cable has a stable connection, there are no kinks. What I was thinking is that there should be something up with my PC, either software or hardware, as everything else I tested was perfectly fine.

 

[COLGeek]

What anti-virus application are you using on the system in question?

 

[SamirD]

If you think it is potentially software, an easy test for that would be to boot a linux live cd and see if you have the same problems there. If you do, it is hardware. If you don't, software.

 

[Diabetes]

The default Windows Defender. Disabling it doesn’t change anything.

 

[COLGeek]

The default Windows Defender. Disabling it doesn’t change anything.

Try SamirD's suggestion. That will help to verify whether a software or hardware issue.