Unless you have a really touchy/specific config that's somehow tied into the OS and specific drivers etc. You should be fine... but, if that's the case, you should be able to save your config, set to default, and reformat/reinstall, then restore your config too.
Usually the only time you have problems is if you have disabled stuff that might cause problems when installing drivers, an example being HDMI Audio disabled, will make Catalyst error during driver install "Device Not Found" etc (though it's not actually a problem in that case)... if you are installing an older OS, you might want to re-enable CSM/Compatibility Support Module if it's disabled.