From LedHed's Wiki
References: http://www.testmy.net/t-12800
It is possible to install Smoothwall on PC without a CD-ROM.
One way is to use a Donor PC to perform the initial install then transplant the Hard Drive/Compact Flash to the new host.
The trick to this is to use a Donor PC with somewhat similar hardware, and when done installing Smoothwall you must alter the NIC driver for the 'Green' interface (eth0).
To change the driver for the Green Interface see: Change Green Interface
Other considerations are the MAC address of the Green Interface, but it appears this is no longer an issue in SW2-SP1
NOTE: Keep configuration changes to a minimum prior to transplanting the Drive.