Saving Lightroom Catalog for Windows Reset

Here you find good articles which files you have to backuped and restored

https://www.lightroomqueen.com/backup-lightroom-files/ 

https://www.lightroomqueen.com/restore-backups/

First, you need backups. Actually, the need for backups has nothing to do with this planned WIndows reset, you should be making regular and automated backups of all of your photos and your catalog file(s). If you haven't been doing this, NOW is the time to start.

Once you re-install Windows, you install Lightroom, you copy the backup of your catalog file to its original location, and then launch Lightroom. If the photos are in the exact same place as before, then you are done. But whatever you do, DO NOT IMPORT the photos. This is so important I'm going to say it two more times.

DO NOT IMPORT THE PHOTOS.

DO NOT IMPORT THE PHOTOS.

DO NOT IMPORT THE PHOTOS.

DO NOT IMPORT THE PHOTOS.

DO NOT IMPORT THE PHOTOS.

Or do I have not to worry since they're already stored in another path than the software (x64) files?

Perhaps you should talk to some Windows guru about re-installing Windows. There are different types of re-installation, some which wipe out all of your data, and some which do not wipe out all of your data. Your plan to re-install Windows needs to be consistent in all aspects with your plan to recover Lightroom, there are details you need to be aware of that are beyond the scope of this forum.

And oh yeah, just in case I didn't mention it, you need to make backups of everything (catalog and photos, and all other important non-Lightroom documents) before you start. This is so unbelievably important that if you proceed without proper backups, then I will have no sympathy for you if something goes wrong.