I thought it worth making note that all of the boot problems may have nothing to do with the CMOS after all, because I finally reconnected the H: drive, that disappeared along with C: a while back, it reappeared and was accessible, but that was by hotplugging it with Windows running. However on the next reboot it disappeared once more. Considering the possibility that it was just a bad connection, I moved it to the SATA slot next to it. BIOS detection hung for a while and Windows saw it enough to install the driver for it, but otherwise it was invisible.
When I opened Disk Management, it took much longer than usual to load the virtual disk manager, and when it did open, it popped a dialog saying that the drive needed to be initialized. I Selected okay, but after some more delay, it popped another dialog saying that it couldn't do it because of an I/O error.
Wanting to separate the drive as far as possible from any motherboard issues that might exist, I installed it in my external case. Again, the BIOS and Windows saw it and Windows installed the driver again, but Disk Management couldn't see it.
Backtracking my thoughts a bit...back on the first reboot, there was an abnormal high pitched hum which was barely audible during shutdown. In fact I didn't noticed it at all, until I heard the pitch of it change a couple of times, and somewhat later, just before shutdown finally occurred, the hum died away in a peculiar fashion. The hum never returned after that.
Also worth mentioning, the drive in question is the one that I posted about recently, which was an RMA for my 500GB drive. In testing it back then, though it passed the benchmark and error scans, on the speed map it had a long line of red blocks (very slow), which was the same blocks that had produced errors on the scans prior to having sent it in for RMA.
Apparently what ever they did to "fix" them wasn't entirely successful, because I had set it up to use for a backup archive for True Image, but when TI's validation of the first backup file hit those slow blocks, TI and the system froze. I continued to use the drive, since the first backup seemed to fill the area with the slow blocks, and the next backups were okay.
I'm going to send this drive back once more, but if I get trash back again, I shall be looking for another brand of drive.