Note: These steps are NOT applicable for SSD drives. If you have received a SMART error, we strongly recommend that you stop everything and make an immediate backup of any and all important data contained on this drive that is not already backed up. If a 'SMART error' has recently appeared on your computer, this generally means drive failure is imminent or has already occurred. One error in particular, however, is more important than others to watch out for.
This set of troubleshooting steps will attempt to get the drive detected again, or to conclude whether the drive has failed and should be replaced. Instead, some error message will occur, and it will become obvious that a serious problem has occurred. So, if the computer suddenly stops detecting the bootable drive, this will almost certainly mean that the computer will fail to boot at all. It is the source of most of the computer's operations. Generally, if a SATA drive is configured as the bootable drive, then the computer relies on that drive to boot the computer and to launch Windows.
My drive's capacity is lower than I expected New bootable drive is not detected correctly
