Internet Issues: The slowest computer in the house

I recently got a new Dell Inspiron 13 i7-5379 and I am experiencing some issues related to download speed.

I realised that the download speed never goes up than 490Kb/s, doesn't matter if its through a web browser (tried several) or a P2P (tried torrent), it never riches 500Kb/s. Tried with the old computer, a surface pro 3 and it goes up to 1.3Mb/s. That made me think it could be a drivers problem, but I updated all of them and still had the same problem.

Moreover, I used a Ubuntu Usb live and there the speed went up to 970Kb/s so same computer but different OS gave different results. That made me think that the problem might be in Windows10 I, I limited the bandwith that windows can use to download updates to the minimum but the speed still is the same.

Tried a speedtest and the download speed was 3.9Mb/s and the upload gave an error, latency was between 100-130. Same test on a Macbook gave a download of 10Mb/s and an upload of 0.9Mb/s.

So the problem is not on the wifi connexion as other computers download faster, seems like it is not in the hardware as same computer with different OS has different download speeds.

Anybody knows what the problem might be?

Many thanks