|Replacing the battery and updating the bios settings hopefully would have fixed the checksum error. The problem with the cdrom is something separate.|
Maybe a little more history of the computer would help. According to specs for the Pavilion a6010e, it came with either a combination cd burner/dvd player or a dvd burner. The bios screen message is saying it's finding a cdrom. Is whatever optical drive you're trying to boot from the original one that came with it? You mention trying to boot from a recovery disk. If that disk is a dvd and you've got a cdrom then it won't boot.
Also, what happens if you don't try to boot from the cdrom and just let it boot normally from the hard drive? Does it go ahead and go into windows or is there some problem with windows (since you're attempting to boot from the recovery disk)?
The best way to test the cdrom would be to see how it works with disks while in windows. The other alternative is to replace it with a known working cdrom.