I had the same problem with my wife's computer. You can get a few flash drives. Use one to copy all your files - Photos, music, video, & docs. use another flash drive, (5GB or more) to get a free copy of windows 10 from microsoft. https://www.microsoft.com/en-us/software-download/windows10. Download the tool to get the O.S.. With my wife's computer, I did not need a product key because the machine all ready had Win. 10 that was registered on it. If you are going to upgrade or put it on a computer that doesn't have Win. 10 on it, you will have to buy a key. After you reinstall your O.S., you can reinstall your files.