Your catalog and the previews folder and other related files are USER files. They are NOT removed or changed if you uninstall Lightroom. They will remain on your computer, as will all your images. The Lightroom uninstall will only remove the files that are required to make Lightroom function.
jim, thank you. i will go ahead and do it then, and then reinstall.
In addition to what Jim has said and just so you are aware, commencing with LR 6/CC it is now necessary for you to have an account with Adobe to register and activate the software. This is so for both the perpetual license and creative cloud versions.
You are allowed two active installations at any point in time. If you are using the perpetual license version and you have activated the program you do not need to be connected to your account. However if you sign out, see the screen capture, you will have to sing in again to reactivate the application. Earlier versions of Lightroom did not have this procedure and users were left to a honour system to limit the two installations (you just used the license key to activate the application. Now this is monitored by Adobe.
You may need to provide more details about your problem reinstalling Lightroom 6.
Hi, I've had LR for several releases and of course they have all been licensed. All of that is cool on my end.The problem that occurred was entirely caused when Adobe installed creative cloud on my computer thru the back door, which hijacked my own existing, standalone software and prevented me from using my own, paid-for software. The elephant in the room here is Adobe's really unscrupulous tactic of doing that, and no one has protested it, that I'm aware of. I am a longtime user of these products, I know my way around, and I explicitly contacted Adobe to be sure I would not be diverted into creative cloud when I upgraded my LR. Two months after my upgrade, these CC icons mysteriously installed themselves on my computer, and a month later- wham, they triggered an override of my existing standalone product and made it almost impossible to get rid of their malware to restore my program to functioning. It's egregious and abominable behavior on a policy level. What a kick in the teeth.
Pls excuse typos; sent from a tiny keyboard.