Issues after installation - Windows

My brother’s Dell laptop had a total meltdown with Windows 10, and the whole system just refused to boot up. I managed to migrate all his data to a different drive, then went ahead and completely wiped the internal disk—including those pesky Windows 10 recovery partitions—and installed Windows 7 since that's what he specifically asked for. The OS boots up just fine now, but it’s acting like the touchpad and mouse don't even exist. It's as if they aren't even plugged in.

What do? I'm kind of stuck on how to go about installing individual drivers when I can barely navigate anything without a working touchpad or mouse...

Which laptop are we talking about here? If it’s only about a year old, I’d really suggest sticking with Windows 10—mostly because almost everything manufactured in the last three years was built specifically with Windows 10 drivers in mind. Plus, since support for older versions is going to wrap up in just a few months, you don't want to be left vulnerable, so definitely keep that in mind... As for the driver situation, if you happen to have an extra USB mouse lying around the house, that should make things a lot easier—you can just head over to the official manufacturer's website and download whatever else you need.