System/Windows files scattered around 2 drives on windows 7.

So, I have 2 HDDs. One of them is an old one that i wanted to remove from the start after grabbing the files onto the new one but then it got forgotten etc..

One another day my PC started having HDD problems so i tested both of the drives and the old one didn't work at all pretty much. I thought what the hell, gonna disconnect it from the pc.
After removing the drive i turned on my PC and it said that some kind of system files or such are missing. I went like Woooo wait a minute, i only ever installed my OS on the one main drive!
Then i connected the drive up again and the PC turned on once again. I went to see the computer management > disk management tab and there i saw it, my windows had system reserved space on the "Disk 1", the old drive but it all boots off the "Disk 0", the new drive.
So i ask if there is any ways i can get the system files off the old drive to the new drive without a need to reinstall windows completly.

Also i wonder why my windows has done such a thing.

Great thanks! I'll try it out right now. Hopefully this will fix my problems with my PC, otherwise im going to need a new system :l

Sorry for double post but I'm in kind of a hurry.
I did it with the software , restarted, disconnected the old HDD,changed the boot drive in the BIOS Just in case.
it came up with this:
https://i.imgur.com/l5ZvEX4.jpg

Reconnecting the drive and my PC is back up once again

PXE is a boot from network.
In BIOS make sure you have Boot from Network disabled and your Hard Drive is the first boot device.

Also, you don't need to teach me everything from scratch, i know how to do the basic things, if things get complicated i get confused :P

Noow. Can i just delete the 100mb partition?
I was googling the issue further and got to this:
Transfer Win 7 System Files to another HD - Computers - Windows 7

I would not delete anything yet!
Always have everything backed up just in case...

I would disconnect the old hard drive and do a Startup Repair.
Startup Repair

Can't i just somehow move the system files to the new HDD? ._.

Cause i don't have a clue the installation disc's location in my house..