Windows 7 - Operating System not found and BIOS not detecting HDD

Hello,
I have HP Pavilion dv9000 series laptop and yesterday it suddenly stopped working (while I was just chatting) and rebooted itself. Upon rebooting, first it stuck at initial screen (BIOS one) for about 2-3 minutes and then showed "Operating System not found".

I checked in BIOS and it seems that it cannot see HDD. In Diagnostics section of BIOS, I tried clicking on Test Primary master but it showed message "No IDE device attached".

My laptop has 2 HDD bays. I tried putting my HDD in second bay and BIOS was able to identify it but still operating system could not be loaded. I guess because this is slave drive bay (I might be wrong though, I am not good at hardware things).

But when HDD is in second bay, I tried booting my laptop using Windows 7 bootable USB drive, and it could see the HDD, but if I put it in first bay and boot using Win7 bootable USB drive, it cannot see the HDD.

Any help/direction would be appreciated. I tried my best looking on google but most solutions either didn't help or didn't apply in my case.

Thank you.

The Hard drive is probably bad. Most computers have a 1 year warranty, I'd check with the manufacture to see if it is still covered. If you BIOS doesn't detect the hard drive you OS will not. If you have some computer skills, you can try putting the hard drive in another computer, if it is SATA, which I assume because you are running windows 7, you should even be able to easily hook it up into a desktop. If it doesn't work on another computer, then your hard drive is dead, if it does work then you have more severe problems with your laptop...