Need to update BIOS for the first time on this 3+ year old Sony and cannot locate anything.

Support Information:
Device Type: BIOS / Motherboard
Manufacturer: Sony Electronics
Model: PCV-RX680G
Interface: USB
Operating System: Windows XP Home
Age of Device: Not specified
FCCID:

Find it on DriverGuide (http://members.driverguide.com/index.php?action=srch&sm=b&aax=&qa6=965&qa5=1&qa7=1500&dp=3&qm0=PCV-RX680G&jmd=and&fzz=d) | Find it with Google (http://www.google.com/search?hl=en&lr=&ie=UTF-8&oe=UTF-8&q=Sony+Electronics+BIOS+%2F+Motherboard++PCV-RX680G+Windows+XP+Home+) | Research manufacturer Sony Electronics (http://members.driverguide.com/index.php?action=getinfo&companyid=965)

http://www.sonystyle.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10551&storeId=10151&langId=-1&productId=11028629 (PCV-RX680G product page)

http://esupport.sony.com/US/perl/select-system.pl?DIRECTOR=DRIVER (support/drivers)

http://esupport.sony.com/US/perl/swu-list.pl?mdl=PCVRX680G&UpdateType=Everything (everything available for this model)

http://esupport.sony.com/US/perl/swu-download.pl?mdl=PCVRX680G&upd_id=101&os_id=7 (bios update)

http://esupport.sony.com/US/perl/swu-download.pl?mdl=PCVRX680G&upd_id=105&os_id=7 (bios update utility)