I'm on Mint 19.1 Cinnamon 64 bits. The WiFi is working, yes, but the signal is very low (around 50-60%). For example, it took almost half an hour to download 150mb of data (which I can do in about 2 minutes in the same laptop but running Windows). Hope this helps!

then it's drivers I'd say... see if you can find a newer version.

Any tips on who to do that? I have no idea how to check for drivers. Could changing the distro to something else help, if everything fails?

find out what the driver name is then search it to see if you can find a newer version, learn how to compile and install from source. and yes it might help changing disros.

with the information on what wifi drivers you're using, then look into what driver the distros you're thinking about trying are using.

https://www.intel.com/content/www/us...etworking.html

That's Intel's support page for the Centrino 6150, which I take it is what you're using. It should also have the firmware, which goes in /lib/firmware. It uses the iwlwifi module, which you almost certainly have.

You need to know that back around 2015 the firmware package in the kernel got cleaned out; somebody cleaned out 'all that old sh** that nobody uses.' I was using some of it, (with a Broadcom b43, released 2007)and suddenly found I had no wifi. You probably are, with your Centrino 6150(released 2010) I imagine you need the firmware. Mint/Ubuntu only supply the kernel firmware package with 'all that old sh**' removed.