Windows 10 download speed is terrible?

I'm assuming that the specs of the new Windows 10 laptop are beefier than your Windows 7 laptop. i.e., faster processor, more RAM, etc.. and you haven't made any specific network adapter tweaks.

The first thing I'd check is to see if there's a NIC driver update available. For example if it's an Intel wireless card check Windows Update and/or the Intel site for more details. Another thing you could try would be to download the latest driver for the adapter and then uninstall the existing driver (even if it's the same version) and then install the driver you downloaded.