This page gives miscellaneous guidance and links related to Microsoft Windows.
A lot of information about the system and software can be obtained from the msinfo32 command. Press <Windows key>-R and in the box type msinfo32. Press Enter.
Installation and Reinstallation
If you need to reinstall a Windows system from scratch but don't have the installation media, you can download the ISO files to burn to your own media for Windows 7, 8.1 and 10 from this Microsoft web page. You will of course, need your licence key in order to perform the installation, and it's also required in order to download the Windows 7 ISO.
If you have no record of the licence key but the system is still bootable then the Magical Jellybean Keyfinder will find it for you. A paid version will even find it from a non-bootable system disk provided you can mount it as an external disk on another system.
Before blowing away the previous Windows installation it's a good idea, if possible, to take a copy of all the vendor-specific device drivers. You can do this using Double Driver. Always try downloading fresh copies of drivers from the vendor website if possible, but copies saved by Double Driver should get you out of trouble if for any reason they aren't available, or if the latest ones cause any kind of problems.