Dell Inspiron 5537: Disappearing disk D/Turning of problem/Boot problem

Hello there,

I have upgraded my Dell Inspiron 5537 with a SSD drive and replaced my DVD-ROM with HDD that I got with a computer. It's been quite a while ago, I've found Dell Windows 8 image online and it's been great since I've decided that I want to reinstall windows with a clean image. I have access to Dreamspark, so I got Windows 8.1 Pro image from there.

Since I've done that my D disk (which is HDD) keeps disappearing. If I restart my laptop it sometimes appear, sometimes not, sometimes for long, sometimes for just a moment. I though, oh what a hell. I will put my DVD-ROM back in and use external HDD, but then, when I tried to turn my laptop on it said that there is no "bootable device" or something like that.

I am 100% sure that I have installed windows on SSD. So, later I put HDD back in and in BIOS I can find both HDD and SSD, but in boot settings there is only HDD and for some reason I cannot turn my laptop on without it, though it has no windows files in it.

On top of that when I try to turn off my laptop it restarts instead.

Sorry for my broken English, but I bet that it's not hard to understand what's the problem. Looking forward for some help.

Thanks