How to roll back from Windows 10 to Windows 7?

Hey everyone.

I’ve run into a real nasty, frustrating headache here.
I did a free upgrade to Windows 10 on my laptop yesterday.
Today, I decided to roll it back to Windows 7 because the new OS was just eating up way too many resources—everything was running perfectly fine until this evening. Now, when I boot it up, neither the built-in keyboard nor the touchpad works. To make matters worse, even when I plug in an external mouse and keyboard, they don't respond at all.
The weird thing is, when I enter the BIOS, the keyboard works just fine there.
I've tried booting into every version of Safe Mode I can think of, but the problem persists... absolutely nothing works.

It's a laptop.
A Dell Inspiron, though I'm not sure if that specific model detail actually matters.

Jacob Flores18 said:Hey everyone.

I've got a nasty, stupid problem on my hands.
Did a free upgrade to Windows 10 on my laptop yesterday.
Today I tried to roll back to Windows 7 because it was eating up way too many resources and everything was fine... until this evening. Now that I turned it back on, my keyboard and touchpad aren't working at all—not even an external mouse or keyboard when I plug them in.
The keyboard works fine in the BIOS.
I've tried booting into every kind of Safe Mode, but nothing works... totally dead...

It's a laptop
Dell Inspiron, but I don't know if that matters.

Sent from my satellite using Reddit

So you rolled back to Windows 7... did you try a system restore to an earlier point?