I got a problem with bt5 i try to get some visual desktop effects, and when i press aplay then the screen turn's black.

i wonder maybe rester give defult but nothing.
after that i try'd to make non-root user and copy whit su password gain root acces to copy kwinrc file but when i try'd nothing happen ...

maybe is there some way i can turn back defult settings from my non root user ?

please help ...

sorry if i said something wrong because i just learning english