Since I’ve already posted about Windows 10, and whether or not to get it and how not to get it previously I’ll keep this short.
If you don’t wan’t to be nagged about Windows 10, don’t want your machine to download its 3+ GB, and don’t want Windows to update you without your permission I have the be-all-end-all solution. This is from a developer that I trust, it is free, it is very lightweight (81k) so don’t blink or you will miss the download, easy to use, and allows you to shut Get Windows 10 down, or toggle it back on later if you decide to upgrade.
While you are at GRC.com you should take a look around as there is much great information, several useful freeware tools, and one great commercial product (Spinrite) there.
Disclaimer: I have nothing to gain from this recommendation, I really believe in GRC’s products.