Most of the time you don’t need a new driver at all. Go to Settings → Bluetooth & devices → Touchpad and make sure “Drag two fingers to scroll” is switched on. If that option isn’t even there, the touchpad driver is missing or the wrong one is installed.
In that case, go to your laptop maker’s support website (for Dell, that’s dell.com/support), type in your model or Service Tag, and download the touchpad driver from the Drivers section. It’ll be called something like Synaptics, ELAN, or just “Touchpad.” Install it, restart, and check the setting again.
If it’s already installed and still not working, open Device Manager, find your touchpad under “Mice and other pointing devices,” uninstall it, and restart. Windows will put it back fresh, which often fixes it. It’s also worth checking that the touchpad wasn’t turned off by an Fn key shortcut.