Proxmox 4: Installation halts when no cdrom is found when installing from USB

[Owi]

Hi...
Instead of upgrading I figured I would install from scratch, but the installation fails testing the cdrom.
I don't have any cdrom attached to this server, and have tried creating the usb in 3 different ways (imagewriter,dd,rufus).
I also tried several usb sticks...

Is there any way I can input a nocd-check in the commandline perhaps?

attached a pic from the installscreen:

 

[wolfgang]

Hi, try to set the bios in dual, legacy or uefi mode.
Sometime this helps.

 

[Owi]

Thanks, but it's an older (though it still feels brand new - time does fly) motherboard (asus p5bv-m) so not much to do there as far as I can see.
I've also tried w/o any other disks mounted - and also 3 different target-drives.

 

[wolfgang]

You can also try to install PVE on top of an Debian Jessie installation
see
https://pve.proxmox.com/wiki/Install_Proxmox_VE_on_Debian_Jessie