I tried the System Restore, but the drive is always in "offline" mode so that I don't have a good restore point to use. It has a message as following: Changes made to drives E:\ after this point cannot be reversed because the drive was either excluded from System Restore monitoring, or was turned off or removed. SSAAD.EXE seems not to be the cause of the problem. I removed it and the problem still exists. I was not able to tell if the disc spinning (I will try harder again). BIOS is able to detect the drive as Primary Slave, just that Windows is not able to detect it at bootup. Something stops it from detecting those plug'Nplay devices? I tried unplugging/reseating of the power and interface cables as well as set the jumper to 'Slave' or 'Cable Select' mode, but none of them make difference. When Device Manager discovers the drive after I force it to "scan for hardware change" the drive is healthy and has no Warning or is disabled. BIOS detects the drive. It is Windows that seems to be "prevented" from detecting these devices. I set the drive to either "Slave" or "Cable Select" with jumper settings, but none of them make difference. How do I find out if Windows is prevented from detecting this device?