BIOS does not boot from ODD or External Drive

I own a 2010 gunmetal black Sony Vaio E-Series laptop (VPCEB23FM)
Specs about this laptop can be found on my profile :)
and I have an issue with my BIOS.

Here's the story:
I used my Samsung 840 EVO SSD for 5 years since I bought it in 2014 and it ran perfectly well until during bootup, it took a very LONG time to reach my Desktop screen. I started getting worried due to the fact that I owned this computer ever since I bought it in 2009 and everything went perfectly well (motherboard, CPU fan, OS, RAM, etc.) until the black screen. I questioned my dad about this and he suggested me to wait until the desktop screen popped up (after about a painful 10 minutes- It did!). I then knew what the problem was. The storage capacity was about over 70% (Remember people, always store data at about 50% or less in an SSD!) and that resulted to slowing down the read/write and boot times on each NAND Flash block. I tried a system restore but that did not work. I started backing up my personal data on two external drives before discovering an option where I could do 'Disk Clean up'.
The most important thing I was not completely aware of were the important system OS log files that were check marked. That went downhill and overboard into a BSOD. I started to panic (Trust me, not that much) and finally decided to get rid of the SSD. Bought a new 512 GB Toshiba Q Series Pro SSD from my local electronics store in Switzerland and started to refresh my mood from being worried and panicked to relaxing relief.
Did everything I was told to do. Flipped it upside down, switched drives, booted to BIOS, swapped Boot order to ODD, then restarted it.
Instead of booting to the Windows 7 Ultimate Service Pack 1 ISO disc, my BIOS still thinks it's set to Internal Disc Drive and resulted me with a No Operating System Found
Dreaded with unsatisfaction, I tried again, this time booting from an external flash drive.
My Vaio flipped out and displayed the same message.

Conclusion, guys. Is it my BIOS or ODD that is malfunctioned? Cuz the only hardware I upgraded into this laptop were the Drives and RAM. I really LOVE this laptop to death and I can't afford on using my New Acer laptop with a crappy European keyboard. I even booted to Safe Mode on my old Samsung SSD and tried to flash my BIOS but it resulted me with a BIOS is already up to date

If anyone here is willing to help me out, it would be great.

Note: I typed this post from my Acer Aspire F15!

Welcome to the forums. Can you test DVD to make sure it boots ok on another PC so you know that's not the fault. Does your BIOS have uefi option which may been turned on if so set to legacy

Thanks for replying.

I checked my BIOS menu and it seems that I don't have a UEFI or Legacy option to choose from.

All I'm able to do is:
-Set the system clock or date
-Choose from Intel Virtualization Tech. or CPU 3/6 Support
-Create passwords and lock hardware / software.
- Set Boot Order (Internal, External, ODD, Network)
- Save changes, Revert Default settings, Save and Exit Configuration, Shutdown.

I also tried to boot the BIOS from an External Flash drive but this time it gave me this message:

"Invalid System Disk. Operating System Not Found"

Is there another solution? :/

To be honest with you, I can't boot to F8.
All I get is a black screen during boot up labelled with No Operating System Found 3 times.
I also toggled with the Num Lock key to make it work but sadly I still get the same black screen.

Have you set dvd to be first boot drive in the bios or it will try and boot the hard drive

I also have a Windows 7 Boot Repair disc by Computer Guy's. I also tried that but I could't make BIOS boot to the ODD once again. Do I need a special boot driver since I (may) have accidentally deleted the important files from the BIOS itself?