How to update the bios of a Dell Optiplex GX280 with Windows XP?

How to update the bios of a Dell Optiplex GX280 with Windows XP?

My computer BIOS for Dell Optiplex GX280 with XP Pro has been failing me miserably. So, I have decived to update/replace the BIOS. Now, my questions are: What files do I put on that bootable floppy? Where can I find those files? Any help and pointers will be gladly appreciated. Thank you!