The CMOS where the BIOS is stored is divided in 2 parts, 1 active and 1 backup. If the upgrade failed but did not corrupt the backup, he might be able to restore his defaults. In the MOBO manual, there should be a section which tells you how to restore BIOS settings (usually moving a jumper). If that fails, he might have to buy a new CMOS for his MOBO. They are not very expensive but he might have to contact the MOBO manufacturer's in order to get one.
Another thing you may try is to download the BIOS on a diskette and try to upgrade it from there. Don't know if you'll be able to with the corrupted/improper BIOS installed but it is worth a try.
My gaming machine:
P4 2.8 GHz
2 X 512 MHz PC3200 in dual DDR mode
Intel D865PERL MOBO
integrated 6.1 MAX audio
Logitech duo MX mouse and KB
ATI RADEON 9800 PRO