Is this the right way to restore my PC to factory settings?

Hi Vass. It sounds like you need to go into your system bios and set your optical drive to be the first boot option. Once you do that your Windows installation should work.

If you are unsure how to get into system bios, then reboot your system and on the bios screen that comes up, it should tell you which key to push to get into bios. In my case, I have an Asus motherboard and I have to tap the f2 key. If you have a motherboard manual that came with your computer you can look at that. The method you chose to install Windows will work. just be sure you have all the data files saved from your old Windows installation to another drive, because reinstalling the OS will wipe your HDD. Also, if you have two or more HDDs connected to your system, then you should unplug (pull the SATA cable) all of them, except the disk you want to install Windows too. That way Windows won't install any system files to another disk, which is a real pain. You need to turn your computer off before you unplug any HDDs, so you don't cause errors on them.