The bandwidth of a network card would generally outclass your internet connection by an order of magnitude.

Gigabits per second network cards have been standard for at least a decade.

And then there’s your wifi too, if applicable, but even that is much faster than your general internet connection, unless you’re far from your router. A new laptop might help you get a better wifi signal, if it had a newer wifi protocol or stronger radio, but that’s also going to depend on your router.

But in front of all of that is going to be your modem. Depending on the quality of your modem that might be a bottleneck.

A new laptop, even the best in the world, won’t make your downloads any faster.

I also back what everyone else is saying. Unless of course you can update your current laptop. What have you got? An extra stick of ram and an SSD can make an old laptop feel brand new, especially with an OS reinstall