MY Laptop model is HP15 AC101TU. Recently I have added an SSD and changed my HDD (Samsung- Seagate internal drive 1 TB) as secondary HDD using a caddy in the place of DVD Drive. When I boot the system, some time BIOS gets stuck and very slowly opens up. Once the system is booted up (WINDOWS 10), my secondary HDD is not seen. The device manager, sometimes, shows as unknown device and sometimes as "SS&4+4;MP% @IJ-MQ 1 BB8 >@'( @;@ ( 8 - 0 GB". Correct driver is not loaded. Once I update the IDE/ATA ATAPI Controller driver as 'Standard AHCI SATA controller', system asks for restart and then the HDD is detected and correctly opens. There is no option in my BIOS regarding HDD exept Boot order. How can I solve this problem? If I connect my HDD to USB port via SATA connector, it works perfectly. I have done the HDD tests and it shows no error. Please help me to solve this problem.