Musescore 3.6.2 sound problem

Installed version 3.6.2 64 bit on my PC Win7 64 bit and find the following strange issue :
-Whatever I do (import score or creating new score and/or putting various instruments )
I get sound only for Piano track (and the sound is "clang") . No sound on any other tracks ....
- I have tried everything , including re-install of previous version 3.6.0 > same probplem
- At the end I tried to install 3.6.2 Portable and it works (sound is "regular " on all the tracks)
What to do ?
PS: it is not a problem from my PC because all the other programs sound very well
Thanks for help