They should be supported regardless of legacy entries in the BIOS. Depending on brand there may be software and/or drivers to install. What operating system and service pack? Also why is this under Windows Recovery CD's? I doubt they have anything to do with this.
Does it work on another machine?
Did you also check the Device Manager to see if anything is disabled? If there are mouse and keyboard entries in Device Manager try deleting them and rebooting, hopefully they will be re-detected.
I forgot to say another question would be, does anything else work in the USB port(s)?
computer is an older (6 to 7 year) Dell Dimension E521 running vista sp2 needing Dell recovery CD. on boot immedate black screen saying possible hardware or software changes cannot boot. note, i was cleaning and removing old programs prior to reboot and problems starting. i can currently enter the bios. from the bios i did the hardware check. mouse and keyboard working. when i boot from CD ER loads but i cannot start the recovery because mouse and keyboard are not responding.