Stupid point - you say it's not working IN the BIOS, does that mean you can use the keyboard to get into it but it doesn't respond to anything you type afterwards? If so that's very strange. The BIOS shouldn't need updating if it used to work, but if it works fine to get into the BIOS that doesn't seem to point towards a hardware defect.
Is it set to boot from the CD first? If so then can you load up knoppix (or similar) and does the keyboard work there? Long shot, but it seems to have got to the point of clutching at straws here.
Another long shot, but if you can reset the CMOS battery (find it, remove it then wait a few seconds before putting it back in again) that might help. By might I mean it's very unlikely but perhaps worth a try