Unity games do not launch but supposedly the file is open in System according to error.

I built my game for Windows (I’m running Windows 10 Threshold 2) but when i try to run it, nothing happens, the cursor stays like this loading in the background mouse windows and nothing happens.

Another strange thing, the cursor is only like that when hovering over the explorer window.
I tried to delete everything and re-build, but when i try to delete, and error pops up “The action can’t be completed because the file is open in System. Close the file and try again.”

Then I tried restarting explorer.exe, didn’t change anything.
I wanted to see if it was an issue with my game or with all Unity games, so I tried to start up another Unity game and the same thing happenned.

Thanks in advance.
~Gorro_Rojo

Try shutdown your Avast antivirus, this helped for us.

According to this:
http://answers.unity3d.com/answers/1097315/view.html