Monkeys,
Have you tried installing the uefi onto a Flash drive?
HP Pavilion p7-1423w Desktop PC Drivers & Downloads - UEFI Support Environment
You might read the following:
Below is a pdf file that explains basic EFI server commands. Published in 2008 for Server Configuration. It may or may not apply to your situation and is offered "as is":
Basic Instructions for using EFI
You might be able to use this Resource to search for more help in using UEFI commands and options:
Microsoft Windows Community – “How To” Search Results: UEFI how