Alrighty, this is going to be horribly written and explained, I do apologize. For reference, I have two computers absolutely identical, hardware wise. I'll refer to them as Box A & B respectively. Since I built it, A has functioned pristinely. All of the parts save for the case were purchased at the beginning of January 2009. I've been having issues with the windows installation on B, and it has gotten to the point where it wont boot at all. Long story (and another issue) short, I pulled the HDD from box B and hooked it up to box A to pull data before a potential wipe. (SATA HDDs, Seagate brand) With the video cards we have, we're pushing (but not over) our power limit on the power supply. Knowing this, I used the power connector I had hooked up to the cdrom on box A to fuel box B's HDD. I pulled the data over and everything, no problem. Then, since I thought this process through, I went to go put in the windows disc to repair the install on HDD B, and remembered that the cdrom doesn't have power. I pulled the power from the case fan and left the case open to vent, and used that to power the cdrom. When I turned on the machine with this setup, my power supply got ANGRY and let out a long beep (presumably to let me know I've overdrawn). I shut off the machine real quick, and replaced the power to the case fan, then just unplugged box b's HDD power and used that for the cdrom. Now, when I try to boot with only Box A's original HDD hooked up, it doesn't recognized the drive at all. I've tried other sata ports and cords, different power setups, and it still wont recognize the drive. I tried the exact same setup with box b's HDD plugged in instead, and it reads and *tries* to boot windows just like normal (the fact windows wont boot, again, another problem I'm not interested in right now) So does anyone have any ideas / fix's / potentials on why the otherwise perfectly fine box A HDD won't be recognized now?