Will uninstalling remove the appdata folder?
 

Do I need to save the plugin folder before uninstalling Calibre to update it to a new version (32 to 64)?

Sorry, I just asked this question already. Having one of those days where the brain isn't catching on quick enough.

No, it won't. You don't need to uninstall calibre if you want updating. Just run the downloaded new setup file.

Edit: Just seen your other thread. In case you want to change from 32 bit to 64 bit it make sense to uninstall. :)

The settings are shared between installed versions (32 or 64). They can both be installed, but you can only run ONE at a time.

The only need to uninstall, is if you need to downgrade a release.
In 99% of the cases, you just leave the settings folder alone.