interference with computer brightness

Hi, recently I've installed mpc 1.7.17.1. It is interfering with the computer(windows 10) default brightness. When I start mpc computer brightness become 100%. After closing mpc or if I active another application brightness goes back to normal. I don't know what to do. Please help.

MPC itself does not touch your brightness setting.

It might be Windows 10 doing it:
Windows Settings > Apps > Video Playback > “Adjust video based on lighting”
(this option was added in 1803)

Your graphics driver may also mess with brightness. For example Intel has an option called "dynamic contrast", and AMD also has an option called "Vari-bright".