How do I restore every setting to the original install settings?

I must have changed something and the sound volume during playback is quite lower than it used to be. And now it's too faint.

I included the screencap but the windows volume level not registering any sound must be a bug, because there is sound playing as indicated by the synth window. and the level is pretty high, but it's not as loud as the default which was set at 50% IIRC.

I hope to restore every setting to the installation default. I uninstalled and did registry clean a couple of times, but that didn't help/