[phunnylinguist]

My 64 bit Windows 7 desktop has always had the most current Calibre version installed. I've always noticed that there has also been a 32 bit version of Calibre installed. In a fit of impulsive behavior a couple of days ago I questioned the need of this additional file so I deleted it, and as per usual then ran Ccleaner. It was then that I discovered that all of the dozens of files and folders in my main Calibre library were gone. As the system had created what appeared to be a restore point labeled Calibre uninstall I repeatedly attempted to resurrect those files and folders; all were unsuccessful.

Now, you may be wondering why I hadn't mentioned cloning or copying all that lost content from a backup, and you'd be right. Plain fact is that I didn't have one. Shame on me.

What remains from the attempts to use System Restore are:
In Calibre Library folder:
metadata_db_prefs_backup.json 15KB
metadata.db 384KB
metadata_pre_restore.db 384KB

In Calibre Library\Unknown\metadata pre restore (3):
metadata pre restore - Unknown.db 384KB
metadata.opf 2KB

In Calibre Library\Unknown\metadata db prefs backup (2):
metadata db prefs backup - Unknown.json 15KB
metadata.opf 2KB

I'm at a complete loss as to how or if there's any chance to retrieve from the above files *any* of what I've mistakenly deleted.

I know I should have asked here first whether or not the previously installed 32 bit Calibre was vital in maintaining the library. My guess now is that I should have left it alone and undisturbed. But besides being vigilant in keeping up a reliable system backup scheme, what steps would you recommend for at least making sure that my Calibre library is properly tin-foiled in the future?