I have an Asus B85M-E motherboard and my D drive randomly disappears. I use to be able to go to device manager and scan for hardware changes and it would be back. It no longer does this. I have checked the disk with crystal disk and it says everything is good with the drive. Also I put a different drive in and it did the same thing. These drives are installed inside as sata. I have switched the power supply cables with the dvd drive (which has never disappeared) and replaced the sata cables, also updated all drivers including the IDE ATA/ATAPI controllers and it still does it. Could my motherboard be going bad or could it be something else. Thank you for any help.