|Kind of hard to tell. When you say one of my drives I guess you mean you have more than one partition that could be bootable.|
Now none are booting.
My guess is they either are all bad or some error with the drive or any part up to the motherboard.
Try a live cd or maybe vista or xp cd and see what it might show.
"Best Practices", Event viewer, host file, perfmon, antivirus, anti-spyware, Live CD's, backups, are in my top 10