I have been looking at laptops for my brother and all of the decent gaming ones I can find are on Windows 8. I read that it is possible to downgrade but many errors are possible. Does anyone know if formatting the SSD / HDD on one of these computers and buying a Windows 7 install disk do download on one would work alright? Also how would I go about doing this, just format it with the disk management page? Any help would be greatly appreciated.
First you must check that the laptop manufacturer has Windows 7 drivers for that particular model on it's website. If they don't, do not downgrade otherwise some of the hardware may not work properly. It would be a mistake to assume that Win8 drivers will work on Win7.
If drivers are not a problem, just boot the laptop from the Win7 DVD and it has a partitioning & formatting tool built-in.
However, my advice is to remove and save the hard drive that's got Windows 8 pre-installed on it instead of putting a different OS on it, just in case you need or want to revert to Windows 8.
Buy a new laptop hard drive to install Windows 7 on. It will then already be totally empty so you won't have to wipe anything off it. Just install it in the laptop, boot from the Windows 7 DVD and install. Windows 7 setup will create and format a partition on the new hard drive. All you'll need to do is press a few keys to let setup know what you want to do.