Hello! I've purchase a 2nd HDD from newegg and it just came in the mail. I plugged it in correctly. It will not show up in My Computer. Now I looked up solutions and I have tried Disk Management and it will not come up. I found it in Device Manager because it installed the driver when I installed the HDD. I also found it in BIOS when I was looking at HDD boot thing and it displayed as #2. Im 90% sure the disk is spinning due to hearing it once it boots and it vibrates when on. I been having a bad week so far and I hope this one isn't DOA! Also It's a Hitachi HGST 500gb HDD.
Check your jumper settings on the drive. you may have a conflict, or if it is 3 or 6 GBs SATA, you should try the pin setting to change it to 1.5 GBs SATA. also try swapping the SATA cables, it could be a bad cable or bad port on the board (or simply dirty) Or try a linux live disk, see if linux has any better luck detecting the drive. if it does see it, check the SMART status of the drive and check the drive's error log.
Before you start moving jumpers, check again in Disk Management. On the right it has TWO panels, and each of them SCROLLS so you can see all it contains. For a brand new empty HDD, it will NOT show up in My Computer OR on the upper panel of Disk Management. Look through the LOWER RIGHT pane for your new HDD - if the BIOS detects it, it really should show up only in this pane of Disk Management. When you find it, RIGHT-click on it and Initialize - or, if that's not the option, Partition and Format it.