From what I gather you're having an issue with uninstalling our desktop app from a Windows device - correct me if I'm wrong please.
Assuming that you get an error upon following the regular process, would you mind opening the "Task Manager" by right-clicking the taskbar and clicking "Start Task Manager"?
Then please click on the "Processes" tab to see if there are any other processes associated with Dropbox that may be preventing Dropbox from being removed from your device. You may need to click "Show processes from all users" to check all processes.
Once you are viewing these processes, if you see any items that refer to Dropbox, or recognize any programs that you may have linked to Dropbox, please perform the following steps for each applicable process:
Click on the line that references the process to select it