One thing that can get in the way, and a new Windows 11 is going to want to do this. A Microsoft Account, as in logging into that computer using a Microsoft Account instead of a local account. This invokes a very intrusive use of OneDrive. OneDrive can really mess LrC up. First off, accidentally actually placing the catalog on OneDrive, bad, very bad. But more often, concurrent syncing with OneDrive. The latter can/will slow everything down, especially if OneDrive access is having a bad day. Would advise creating a local account, you do not need to login to a computer using a Microsoft account, and if you do want to access OneDrive, that can be done while logged onto a computer with a Local Account. I am not sayeing that the Microsoft account by itshelf is an issue, I am saying that it invoked OneDrive, and that is an issue (if yoyu really want to use a Microsoft account, their is a way to turn any OneDrive association with LrC off)