How can I backup/save my game save data in Windows 8.1?

I need to do a clean install of windows on my machine; but I don't want to lose my game save data. Where can I find it on my computer so I can back it up?

I assume it would be the same as Windows 7, so go to My Documents, then in the bar at the top type "%appdata%". From there go to ".minecraft" (it might be hidden) and then saves.

If the folder is hidden, you will need to press ALT, and go to "Tools" at the top. Then "View", and check "Show hidden files and folders"

1) Open up your documents

2) Type "%appdata%" in the bar at the top

3) You should see a folder called ".minecraft" and inside it is one called "saves"

4) Back up the saves folder

5) Re-install OS and then install Minecraft

6) Go back to .minecraft and copy your saves into it.

@believer258: thanks for your help, this work perfectly