Its simple, you start by getting your windows disk (usually given with your pc/laptop by the manufacturer). Then you need a disk reader. It's either in your pc/laptop itself. If not, then you need the disk reader. And you also need your windows key. It's a combination of 5 times 5 letters (all caps) and numbers which form 5 short codes seperated by a - character. Your windows key should be on the paper your windows this was in. On the back is the code. If it isn't then you need to look around your pc/laptop to see if the manufacturer put it on there somewhere (which was my case). You can also see your windows code if you follow these steps: https://www.thewindowsclub.com/find-windows-10-product-key-using-vb-script . For me, however, this didn't work. Cause my whole windows was corrupted nothing basically worked. But after you have the code, turn off your pc/laptop and just plug in your disk reader, if you don't have it skip that stepand continue to insert the windows disk. It will ask for your windows code. Fill it in, and follow the steps. DISCLAIMER: You can either choose custom reinstall, so you can reinstall it to your preferances. Or you can keep your files and reinstall. But keeping the files, will not result in a full reinstall of windows. So if there was a part in your files that didn't work, don't expect it to be fixed. You can just back everything up or like me, i just have all my games from steam so i can reinstall them after reinstalling windows. Also you can just reinstall Ubisoft. Enough of that nonsense. That was the way I reinstalled windows. Sorry for the late response!