As shown on this page, there are many ways that you can try to fix the internal hard drive not detected issue. For a new hard drive, you can first initialize the disk and then create partitions on the drive.  For a used hard drive, you can try these tips as shown on this page in Part 2: 1). Change the hard drive letter; 2). Recover lost partition data and create new partitions; 3). Update hard drive driver; 4). Check hard drive connection, enable it in BIOS; 5). Repair damaged hard drive