Hello everyone,
I have an Acer Predator G5920 with a 2 TB HDD and a 16 GB SSD for several years now, which started running really slow one day during this summer's heat. Checking task manager I saw that the HDD had 100% activity constantly and this seems to be a bad sector problem with the HDD drive according to the internet (to me it feels like some bitcoin farmer has hacked my computer and is using my computer to mine cryptocurrency or something XD).
So I bought a 250 GB SSD and replaced it for the HDD, but to my surprise the BIOS doesn't recognise this as a drive at all.
Plugged the HDD back in and plugged the 250 GB SSD in as a 3rd drive next to the 16 GB SSD already in there, and then the BIOS suddenly does recognise the 250 GB SSD. o_O
I put an Ubuntu MATE OS on the 250 SSD for testing and after some hiccups I managed to dual boot it with Windows 10 OS on the HDD, working both fine under the circumstances.
Unplugged the HDD again to see if the BIOS will recognise 250 GB SSD now, but I got a big nope again.

What I want to achieve is the following:
the 2 TB HDD -> delete all the 7 partitions and have just one big giant 2 TB partition for storage purposes only,
the 16 GB SSD -> remove the partition that's on it and replace it with a partition with some small Linux OS or something,
the 250 GB SSD -> make this my main Windows 7 OS drive (because I am sick of Windows 8, 8.1 and 10 frankly),
however what is stopping me doing this, is the current BIOS refusing to recognise a SSD as a drive I can boot from, so my question to this community is this: