As if I didn't have enough trouble, while trying to solve the problem with my extra hard drive, I locked myself out of my laptop. My mistake was that I went to BIOS and set the passwords (same for user and HDD). I did it thinking that may be it will help me to have more permission (know it sounds stupid, but I am out of options with all these "permission denied" messages.)
I am 100% positive I have the right password for the HDD. First, because I used the same password I've been using for a while now. Second, when I entered it, it asked for a second time for confirmation.
Now when I start my laptop, it asks me for a password, which I type and it says "certified". Then it asks for a HDD password (which was exactly the same). When I type it, it says "uncertified" , and aftfer 3 attempts it shuts down the computer.
Was thinking I could get to BIOS and changes the settings since I have the password that could get me through, since it is "certified" , somehow it doesn't let me into BIOS. I tried f12, f10, f2, ctr+s, del, f9. ..
Called Toshiba, but they only said that I should get a new hard drive. I guess they didn't take it seriously that I didn not forget my password. I asked them if it's possible that the password for HDD was modified somehow because it was exactly the same, and may be it's not allowed. Didn't get an answer, the guy was not very helpful and had long pauses, seemed like he knew even less than I do lol
If anyone had a similar problem or have any clue or guess what can be doen, please reply! Thank you!

use the jumpers on teh mobo to flash your bios to defaults, then pull your CMOS battery out and let it sit out overnight. That should allow you to get back into the BIOS and remove the HDD password.

When you set a password for a HDD, the password is stored in a protected memory location on the hard drive itself. This is to prevent it simply being removed and placed in another machine. In this sense it is independent of the BIOS password.

Is this the original HDD for the laptop or a replacement? The boot drive or a second data drive?

Is there data on the drive you need to recover or would you be ok with wiping it?

Thanks a lot! I am going to try it and post the results.

It is a replacement, the original was damaged just recently. It is the boot drive. All can be wiped. I haven't put anything on this drive since I knew I might have to reinstall the OS again. I've been trying to recover the folders from the old hard drive and had a problem with copying the folders or mounting the external harddrive (in enclosure). I have a couple of threads about it here. Now I got myself in another trouble. Sigh

Unfortunately my laptop is not the kind that has several sections on the back that you can just open and see the whole motherboard. I will have to completely disassemble it to get to the motherboard. Not sure if. A finish it tonight. I am still reading about some other ways and wonder how could my password change? If I pressed a wrong key by accident, then when I was typing the confirmation there would be no match, right ? It doesn't make any sense.

You can use hdparm to reset the HDD password. You will need to be able to boot a live CD/DVD/USB image.

This page should provide the needed steps and some additional information for troubleshooting the proceedure.

https://ata.wiki.kernel.org/index.php/ATA_Secure_Erase

hi NyteOwl,

Thank you for the suggestion. I would love to try it, but my problem is that I can't get in to use the terminal. I can't even get into the BIOS.
If I put Zorin CD in and start the computer, I can hear the CD being activated, but then I get this black screen with the password request. After I enter the password, it asks me for a HDD passport, which it wouldn't accept. That's why I am stuck. Spent all day yesterday trying to get in BIOS , no luck.
I even tried to start the laptop without the harddrive, btu with the installation cd in. Then in the midle of the process of installation cd activation put in HD and take the cd out. It is risky since it can damage the HD, but I felt like I don't have much to lose. This method works on some laptops, but didn't work on mine.
Then I downloaded a program called knoppix, but it didn't help me, it just doesn't go anywhere. Same black scree, no matter what keys or buttons I push on the start up.

I am a genius! Lol
As I mentioned earlier I knew the password and I was suspecting that it wouldn't certify itjust because I had exactly the same password for the user. Wish they had a warning about it somewhere.
Anyway, my goal was to get to the BIOS to try to change the password and I spent 2 days without any luck.
Then I got an ideanthat if I start the computer without any HD and any CD or USB, and keep pressing the F2 on the start up, may be then it would let me in since I have no HD hence no password required. It worked!
The problem was that there was not such a option as HD password set-up for obvious reason
I went ahead and changed my bios password, since it let me and I suspected that they should be different. Then I thought that I could try and connect the HD and may be the option to unlock/ disable the passowrd would be available. Nope, it didn't work. You have to restart wi the HD attached to see the option of course.
When I restarted it, it asked me a password, which I had just changed and it was certified. The. It asked me for a HDD password and the old password that didn't work previously worked as a charm.
Lesson: try to be more diversified with the passwords because you never know...
Thank you Kustom42 and NyteOwl for your help!