I can't move my Dropbox folder from D: to C: after reinstalling the app

Welcome back to the Community, torrmundi! 

Has your Dropbox app finished syncing, since you reinstalled it on your device? 

If your d:\ drive has the most updated copies of your files, and you don't need the copies that have synced to your c:\ drive, you can pause the app's syncing, unlink it, delete the Dropbox folder that has been created there and sign back in. 

This time, after signing in and choosing which folders to sync, and before you click on "Open my Dropbox" folder, you should see an Advanced Settings link, and when you click it, you can choose the parent folder of the already established Dropbox folder. For example, if you have your Dropbox folder in the path "D:\OtherDrive\Folder\Dropbox" you'll want to select the folder "D:\OtherDrive\Folder". 

After this, the Dropbox app should just reindex your existing files, instead of downloading everything anew. 

Hope this helps! Let me know, if you need more help though. 

Yes, sync onto c: is finished.

The Unlink hyperlink (https://help.dropbox.com/account-access/sign-in-out#How-to-log-out-of-your-Dropbox-account) doesn't show unlinking, it shows logging out. Are they synonymous?

After logging out of Dropbox (I assume that is what was  intended), I cannot copy from c: to d: or even f: (a micro SD device) files - they are all read-only. Oddly, Disk Management shows c: d: and f: as Online, not Read Only status.

Ok, I deleted the c: Dropbox folder, and after selecting folders for sync, I directed Dropbox to use d: root as the new folder. It replaced that with d:\Dropbox (as I intended). But then it gave a warning message: "There's already a folder or file named Dropbox. Dropbox will rename your existing folder or file named "Dropbox" to finish installing"  That's ominous - it seems like it will download all the files instead of reindexing as you said.

Yes, you’re correct; unlinking and logging out of the Dropbox app are basically the same thing (sorry, I should’ve clarified above). 

About the error message you mention after assigning the Dropbox folder to your d:\ drive again, can you select the parent folder of the filepath, like in the example I mentioned above ("if you have your Dropbox folder in the path "D:\OtherDrive\Folder\Dropbox", you'll want to select the folder "D:\OtherDrive\Folder”)? 

Does that help?

I tried to make that clear that I have done that. The actual folder is d:\Dropbox. I entered d:\ (the root of d:). It then changed that to d:\Dropbox and gave the error when I saved.

Hmm, I see. Can you upload a screenshot of the error you’re getting, as well as the actual location of the Dropbox folder on your d:\ drive? 

I’d like to have a visual and check what else we can try.

Here you go.

Hey torrmundi, sorry to jump in here.

Without renaming your old Dropbox folder, this won't work, I'm afraid.

You'll need to rename your existing Dropbox folder to "Dropbox (old)" or similar. 
 

Then, once you select the location that you want for the Dropbox folder and the app starts to sync, you'll need to pause syncing.

 
Then, move only the content of "Dropbox (old)" into the newly created Dropbox folder. 

When the move is complete, and not before, resume syncing.

Hannah, thanks for jumping in. But your solution has a problem. After renaming d:/Dropbox to d:Dropbox (old) and then restarting the Dropbox app, selecting the new location as d:/, then stopping sync, I tried to copy folders from d://Dropbox (old) to d://Dropbox. Some folders would copy, but most fail with some sort of copy protection error.  I then Quit the Dropbox app, rebooted, and retried to copy. Same problem.  Windows Explorer said: 

What if I change my Dropbox location to d:\\Dropbox(temp), say.  Then copy from d:\\Dropbox (old) to d:\\Dropbox. Then change my Dropbox location back to d:\\Dropbox. Would that work?

Hmm, is it possible that you're trying to copy files that were online-only and not available offline?