Problem solved
Issue was actually my HDD which isnt working anymore. Since it was connected with my ssd my Mainboard made this sound to inform me something is not working.
The Stuck in bios was also cause of the HDD
Hello
long story short,
PC makes 1 beep sound once in a while since I played Diablo 3 on my HDD. Got Freezes, long loadingscreen ( Only in Diablo 3) while my Task Manager said everything is alright and I even do other stuff in the meantime.
Swapped Diablo 3 to my SSD and it works totally...