Supervisor Password Quit Working

[millsbass47]

I recently purchased a used Toshiba Satellite C855D-S5320 Laptop from a friend, basically for a song. When I made the purchase, the owner gave me the Supervisor Password in order to get online. I guess that you could call me computer illiterate, when it comes to all the jargon, and tech talk in the computer world. All I was ever interested in was surfing the web, and nothing more. And, in the past, if I ever ran into a glitch, Google was my friend and got me through it. Well, this time, I may have bit off a little more than I can chew. After getting the laptop home, I realized that it was running pretty slow. And, from what I deciphered from Google, a reinstall of Window 8 was in order. Now, please forgive me if my description of the problem sounds a little ham-fisted, as far as the technical jargon goes. From what I gathered online, a reinstall of Windows 8. From what I gathered I was supposed to access the UEFI, and switch it over to CSM Boot. And, now, for reasons unknown, the Supervisor Password no longer works when I'm required to type it in on the screen that says: "Enter Supervisor Password or hit F11 key to proceed
F11 key limits functions."
When I type the password in it says: VERIFY ERROR!! Press ENTER to continue", then it returns back to the "Enter Supervisor Password" link again. What gives? I'm just about ready to pull my hair out.

 

[USAFRet]

Sorry, but Tom's Hardware has a strict "no assistance" policy on passwords
http/www.tomshardware.com/forum/id-2317969/read-passwords-lock-codes-pin-numbers.html

Ask the previous owner.