Dragging and drop issue desktop

As other people have said, by default, Dropbox uses a folder on the local drive (normally C:\users\<username>\dropbox) and then it syncs that folder to the cloud - so because the folder you drag files to is on the same drive as the files (unless you have you're files on other drives), then the OS will move them rather than copy them - highly annoying!  

There is a simple solution though - you can move the dropbox folder to a virtual drive (still on your main C Drive) - it's easier than you'd think (in Windows at least - but may also be possible on a Mac?).

Note: You could "shrink" your primary partition and create a new one on the same physical disk but that's a bit heavy handed and would reserve a physical / fixed amount of storage for dropbox which is a shame. A virtual disk can be used like a normal hard-drive but can dynamically expand so it only takes up the space your files are using. 

To create a Virtual Hard Disk (VHD) in Windows:

• Hit the Windows key, type "Computer Management" - and run the app.
• Click on the "Storage" section and then "Disk Management"  - this should display the disks / partitions you have.
• On the "Actions" menu, choose "Create VHD"
• Follow the wizard - choose a folder location for the disk image file, a max size etc (e.g. 2048MB for a 2GB free dropbox account)
• Select the 'dynamic' size option and continue 
• When you're done, you'll have an "unallocated" partition. right-click on the "drive" part (on the left) and choose "initialise"
• Then right click on the unallocated portion (on the right) and choose "New Simple Volume"
• Follow the prompts and give it a drive letter (e.g. D)
• You now have a D Drive in Windows Explorer! By default it'll be called "new volume" but you rename it by right-clicking and choosing properties (to DropBox or FileSync - or whatever you like).

Now go to Dropbox settings to switch to using the new drive:

• Click the dropbox system tray icon, click on your account icon (your initials in a circle) and choose "preferences"
• On the preferences/settings page, choose the "sync" tab on the right
• On this page, you'll see the default C: drive folder location with a "move" button next to it 
• Choose "Move" and navigate to the new DDrive (you'll find it under "My PC").
• Dropbox will create a "DropBox" folder on the drive and move the contents over from the old folder.

That's it!

Now when you drag files onto a dropbox folder, Windows will see it as a different drive so will automatically copy rather than move by default (of course, you can override if you do want to move a file)