Dropbox - how to retain files but reinstall dropbox?

I have to reinstall windows and I have a lot of data on dropbox (~30 gb). I'm afraid dropbox will start syncing all over again. I want dropbox to keep the current files in my harddisk after I reinstall windows. (files are in a different drive, obviously)

Dropbox path should be same before/after reinstallation. I just made the same thing, I bought a new laptop. I moved my old dropbox folder into my new laptop. By using settings in dropbox, select the dropbox folder --> you should show your actual folder to the new dropbox setup.

Note : DO NOT FORGET to backup actual dropbox folder into external hdd in order to avoid bad results.

Probably late, but because I was looking for that as well, here is the official procedure from the Dropbox documentation.

https://www.dropbox.com/help/1941/en

It looks like Laurent's answer is the right way. I seem to remember that SE likes the core part of the answer to actually be posted on SE, so here is what the DropBox documentation says, from the same link (https://www.dropbox.com/en/help/1941).

Basically, on the new computer or in the new location that you want DropBox (DB) to put the new DB folder:

• Start a DropBox Sync from scratch to the new location, so that DB actually starts downloading all the online files to the new location.
• Pause the Sync, to stop the downloads.
• Copy your existing DB files into the new location (overwrite anything that was just downloaded).
• Resume Syncing - DB will first check the DB folder, be astounded to find all the files magically there, and proceed to only sync the latest updates, if any.

To clarify how to start a DB sync from scratch in a new location (for example, in the event of already having all the files on a hard drive but in a different location, like myself & the OP), I had to actually

• Unlink my DropBox (Prefs>Account>Unlink).
• Re-Link it and point to the new desired location.
• Pause the Sync
• Move all the DB files from the old location onto the new location, overwriting anything already there.
• Resume Syncing

In my case this worked perfectly, and DB was "up to date" after a short while. Again, thanks to Laurent for the link with the answer.

By the way, on DB v3.0.3, simply changing the DB folder location to whereever my existing folder was (as per the other answer) did not work; DB stated "There is already a DropBox folder in that location" or something to that effect.