The Neoware CA10 has a standard PC Award BIOS - hit the DEL key on power up to get into it.
The boot options are
There is a USB pen-drive creation tool in Tinycore Linux. I had previously used this to make a bootable pen-drive that I used quite happily with the Fujitsu Siemens A250 so....
I set the "First Boot Device" to USB-HDD and the "Second Boot Device" to Disabled, plugged the pen drive in and booted the CA10. This worked perfectly - unlike my experience with the CA16.
My CA10 is running Windows CE 5.0 (Neoware Rev 8.0.3 (Dec29 2005))
In Windows CE there is an option to set an Appliance Password. If one is set you cannot make any changes to the system configuration without providing it. You also may be prevented from actually viewing any of the configuration information.
If an unknown password is set this obviously is a barrier to you using the standard firmware. You need to reset it. Unfortunately I'm not aware of any simple key combination to do this but there is a relatively easy route you can take. In the description below you may need to adjust some things to match the Linux distribution you use. In my case I'm using Tiny Core and the DOM appears as sda.
$ sudo su
#
# mount /dev/sda1 /mnt/sda1
# cd /mnt/sda1
#
# mv system.hv system.hv.old
#
# cd Profiles/default
#
# mv user.hv user.hv.old
#
That should do it. The .hv files are 'hive' files that contain the system configuration data. Windows CE will recreate these with some default entries when it next starts up.