I remember having to download Japanese drivers to get I think the DualShock 3 controller to work on PC. Now you just plug the thing into the PC and it works with Steam.
Whenever you're doing something you think might break stuff or a major kind of update, image your C: drive first. Then if something goes wrong, you just restore that image and you're back up and running in like 5 minutes. Imaging software is more essential than anti-virus IMO. It's basically a glorified copy/paste.
The product key is embedded in the BIOS nowadays and you can download a copy of a stock version of Windows from Microsoft and install that using the key in the BIOS you did buy as part of the cost of the PC.
Use this Windows 10 Product Key Tool (free) to easily retrieve your Windows 7, Windows 8.1, and Windows 10 product key from BIOS or EFI.
www.intowindows.com