I have 2 laptops, one via ethernet gets 870 Mbp/s download via speedtest while the other fluctuates between 150/450 Mbp/s. To make sure it wasnt a placebo effect I brought the malfunctioning laptop to the exact same ethernet cable and did a speedtest, as expected the working laptop got 870 download while the malfunctioning one got 260. I've tried all command prompt solutions and went to network and sharing centre to reinstall drivers. I don't know what to do.