Web player will not uninstall or install.

I originally installed Unity 3D for class, and when I built and ran for the web, the webplayer worked and my project worked. But I have to upload the .html to dropbox or google drive. However, when I uploaded to dropbox, it said I needed to install the webplayer. So I did, and but the program stopped installing. I checked out the details and it said it had uninstalled the player that had been on my computer. I forced the installer to quit, and rebooted my computer. I tried to uninstall unity and unity web player, but only unity 3d uninstalled. The uninstaller for unity web player starts, but then it disappears.

Despite rebooting, when I try to run the installer or uninstall the web player, it says an instance is already running. I am reinstalling unity 3d right now and the editor and mono have installed but it is currently stuck on installing the web player.

Any help is appreciated!