I took a big risk and installed it a couple of days ago without backing anything up... so far, so good.
Git yerself to a big comp store and get an external hard drive, Red One -cheap and fast. I'm still using XP and even Widows 98 on a separate computer for old games.
My point is that well fermented pre owned food happens. I've lost my computer four times and none of the events were the operating system.
One motherboard that lost it's marbles and corrupted all data.
One flood which totaled everthing. The comp didn't even get wet. Just 99% humidity from a few inches of water in the basement -which corroded everthing.
One lighning surge which took out 3 internal hard drives, the motherboard and floppies.
One trojan horse that got thru and @#$%^&*)+ ed everthing.
I had a Syjet which wrote to hard drives cassettes in those days and most data was backed up. Now, I have three external drives which are only turned on for backups.
Of couse there is always those pesky meterorites.