So what I am looking for is a way to prevent anyone from booting from a USB drive on this specific Dell Inspiron 5559.
so normally what I would have to do is to set an Admin password in BIOS that would prevent anyone from booting using a USB drive or change BIOS settings without the Admin password, but the bad thing is the admin password could be easily bypassed using certain websites with the System Serial that appear in the message asking for the admin password, I won't post links here but you can search on Youtube and see for yourself.
so apparently that doesn't work now I have windows 10 installed and I can use Bitlocker to encrypt my HDD and protect my Info but I am also trying to protect the HDD from sabotage ie formatting the HDD (without using external backup Drive).
In short I want that if someone wanted to tamper with the laptop they would need to open the laptop casing and take the HDD out (or even the cmos battery if they tried to reset the BIOS settings) and I am OK with that.