install fujitsu d3644 usb bios

I want to install Proxmox from USB on Fujitsu D3644 with BIOS 1.6. In the menu "Welcome to Proxmox Virtual Environment" I select "Install Proxmox VE". After some tekst, the PC starts to reboot. I have selected “disabled” in "Secure Boot Control" (Secure Boot - not active). According to the...