Quartus II 15.0 Hanging at Startup

Hello!

I recently installed Quartus II 15.0 Web Edition, and it was working well. Later I installed Quartus II 10.0 Subscription edition from some installation media that came with a DE2-115 board. I installed that because I thought that version included a license for the subscription edition (which it turns out it doesn't). Once I discovered that it didn't include a license I uninstalled Quartus II 10.0. Subsequently I installed Quartus II 15.0 Subscription Edition in order to try setting it up with a license from my university. That might work out, but in the meantime I couldn't afford not being able to program the development board, so I uninstalled Quartus II 15.0. After this however, when I tried to start Quartus II 15.0 Web Edition the application would hang at the splash screen.

To try to solve my problem I uninstalled and reinstalled Quartus II 15.0 Web Edition, but it still hung at the splash screen. So I tried to uninstall it again, and deleted the altera environment variables, registry entries, and user setting files, and then reinstalled Quartus II 15.0 Web Edition along with the 15.0.2 update, restarted my computer (prompted by the update installation), but the application still hangs at the splash screen when I try to launch it.

Has anyone else experienced this problem? How can I troubleshoot why the application is hanging?

Thanks!

Tim