[SOLVED] One of two computers on the same Ethernet setup is all of a sudden much slower than the other

[fromtheveldt]

I have an internet plan that is within the 100Mbps-200Mbps range, and have two computers in my home that both use wired connections. Up until recently they've been fine, but now I'm starting to get speeds of only ~20Mbps down on one while the other remains at full speed. I'm not sure what could have caused this, or what exactly are the best steps in order to troubleshoot and restore the wired connection to its full speed.

I've tested the connection using Speedtest, Fast.com and Xfinity's speedtest.

 

[Ralston18]

Are both computers directly connected to the router or do the computers use different connection paths?

Any Ethernet wall outlets, power line adapters, switches, what is different between the router and respective computers?

Swap the Ethernet cables between the two computers. Does the slowness follow the Ethernet cable or stay with the slow computer?

Manually download the network adapter's drivers for the slow computer. Reinstall and reconfigure.

Make and model router? The router's logs (if available and enabled) may prove helpful. Who has full admin rights to the router? You will need help from that person.

From each computer run "ping" and "tracert" via the Command Prompt targeting the network router's IP address.

Any differences in statistics and times?

 

[SamirD]

And if you try all that and you still don't see any changes, boot a linux live cd/usb on the slower computer and see if it work correctly. If it does, it's a windows software issue.