EDIT: The latest download from the Spotify web site installed properly and the Windows 10 desktop program is now working again with no issues. If this doesn't work for you, sorry - I've seen that many people have this problem and that there are numerous solutions, but mine appears to have more-or-less fixed itself.
Before I begin: I've done a Google search and tried many of the different methods, such as deleting all items in certain folders (Browser and Storage) or even the folder itself, but to no avail.
Even before I resorted to all that, I tried to uninstall the program through the "Programs and Features" on Windows 10, but that itself presents the same issue.
Whenever I try to run the desktop program, you see Spotify appear in the Task Manager and from there it does **bleep** all. If I try to open Spotify again, another instance appears in the task manager, but it does the same thing (which is **bleep** all).
The kicker is that when I try to uninstall, it does the same thing - so I actually cannot uninstall the program. I trying running the installer file in the Update folder but to no avail. I tried downloading a file right from the Spotify website, and once again, it didn't work.
So, there you have it, I can't actually uninstall the program because the program is being a **bleep** and I've wasted half an hour searching through past posts where people have solved this issue, but none of the proposed solutions have worked.
I'll use the web player in the meantime, but this makes no sense whatsoever - the program has worked recently (within the past week, or at least couple of weeks) with no issues, and this issue has come up for no reason that I can tell.
If you guys can help, great; if you can't, thanks for trying. I'm just a bit upset at the waste of time at trying to get a program to work that has had no issues since I started using it.