PC Stuck in BIOS-Bootupscreen

After starting the PC I am stuck in the Bios bootup screen. All connected devices light up and get power, but inputs are not recognized. The graphics card still displays a picture. Sometimes when I start the PC it works normally again. However, it sometimes happens that I get a blackscreen after executing exe files, while in the task manager in the performance tab disks are not displayed although they usually are. I also use an M.2 SSD that has the operating system on it, plus I have an HDD connected to it that also has executable operating system on it. To fix it I unplugged the GPU from th