If you uninstall and reinstall 5 times, you won't lose any of your installs, you'll get them back after uninstalling. You just have to be connected to the internet, that's it.
From their forums.
That's a lot better than I originally thought. I've installed and uninstalled and installed over and over because of reinstalls/system upgrades etc. Just have to remember to uninstall before I reformat or anything.