Please let us know which versions of Opus and Windows you are using, and link your account.
Generating a Process Monitor log of what happens when you try to launch Opus may help us determine where things are going wrong.
Besides changing some folder formats, Opus is still on the default settings, but it is not "starting up", well it does start up, but no GUI window appears nor a icon on the task bar.
How did you change the formats if you can't launch the program? Is there a detail missing here?
If you run Opus a second time, do any windows open then? It may just be configured to run in the background and not open any windows the first time you run it.