If we bought a PC with pre-installed Windows 8.1, in most cases we don't get a full Windows installation DVD. Just a "recovery partition", with all the manufacturer's useless apps. Thankfully, Microsoft allows us to download Windows 8.1 ISOs, for an entirely clean installation.
Laptops with preinstalled Windows 7 have a sticker with the product key under the laptop. Laptops with preinstalled Windows 8 or Windows 8.1, however, never have such a sticker. The reason is that the Windows 8.1 product key is embedded into the BIOS or UEFI. Here's how to get it.
Windows throws a blue screen when there is a fatal error, severe enough that it is impossible for the operating system to recover without resetting the PC. There is a reason we refer to it as a Blue Screen of Death (BSoD). Let's see how to diagnose a blue screen.