Does Windows 8.1 Setup delete everything?

Hi guys, I'm currently using windows 7 and want to install 8.1

I just launched the setup, and on the window where it asks what to keep, the only option is 'Nothing'.

Does windows 8.1 setup delete everything I've got on my current partition, or will it transfer my current system into a windows.old folder like Windows 7 Setup does?

Because I really need to keep my files.

All of the upgrade paths and options are listed here. It will also tell you what you can save and what you will lose.

Windows 8 Upgrade Paths

Good luck.