Cannot boot from CD or external USB

[compdoc]

> As far as I remember the order:
> 1)    CD drive
> 2)    external USB drive
> 3)    internal HDD
> 4)    LAN (?)
> But I can move ONLY up and down through that list. The enter key does 
> not work.

Highlight the drive in the list you want to change, and press the + or -
keys. Then save the settings as you exit the bios.

That should get your usb stick to the top of the list, but it won't solve
the problem of the non-booting CD. It doesn't sound as if you are trying to
boot a DVD in a CD drive, if you can read the files after booting, as you
said.