Solved Can't select the right drive for re-installation of Win7

I have a Gigabyte P37X v5 Laptop with Windows 7 pro, a Samsung 256GB M.2 PCIe SSD, which is the C:\ Drive and a Hitachi 1TB 7200RPM SATA III for storage.
I want to re-install windows on the Samsung M.2 drive but the installation only offers the option to install it on the 1TB Drive. The Samsung drive is not listed. How can I get the Windows installation to recognize the M.2 drive so I can reinstall it there? I'd rather no remove the 1TB drive to force it. Will that even work or is there another way? TIA for any help with this.

Yes the drive is BIOS and is already set to AHCI mode.

Here's an update on the state of my GIGABYTE laptop.

After checking all available info on the net and still having no success, I decided the remove the M.2 SSD and install windows on my SATA III storage drive just to have access to the machine. Yes, it's slower than molasses in Jan but at least it boots and runs sans problems. This was a brand new laptop from xotic.pc. I opted for win 7 because I hate win 10. I had problems from the start with BSOD's (driver_power_state_failure in ntoskrnl.exe) which were only related to the use of sleep mode. Avoid sleep mode, no BSOD's. But who wants to be stuck with hibernate or shut down? Device Manager claimed that all my drivers were OK. They were also more up to date than what was available on the GIGABYTE web site. I have no idea where xotic got those drivers because they weren't on the accompanying driver disk from GIGABYTE either. I also was not able to restore the system from any created restore points. Windows error message, "unable to restore". Frustration mounting. Then I did a really stupid thing. I tried replacing ntoskrnl.exe with one from another windows 7 installation. Bad move. Couldn't boot at all. Bend over, bend knee sharply, kick butt. Repeat.
The results of my SATA III installation are, Windows is, of course, S-L-O-W-W-W but steady. No errors. Sleeps like baby, No BSODs, restores to another restore point. So I have concluded that either the windows installation on the m.2 was corrupted from the start or there's something wrong with the drive itself. I am about to reinstall the drive, try to access it through file management, replace the original ntoskrnl.exe and see if it will boot. If it does, I'll try removing all the software I installed, and see what happens. "WhoCrashed" reported that it thinks the problem's not hardware but possibly a third party driver. If I still get errors after removing all the software, my next plan is to clone the SATA III drive to the m.2 and hope for the best. Stay tuned. Thanks again.

Uadate 2
This machine has given me no end of grief. I did finally get windows installer to see the drive but it wanted a driver which I couldn't find on the Samsung or GIGABYTE site. It's an OEM drive. But I did manage to locate a Samsung driver that, although it still wouldn't let me install windows at least the drive showed up in file management so I cloned my SATA lll storage drive which I had installed windows on. The clone appeared to be successful but the drive kept stalling at the windows welcome screen even though I disconnected all USB devices before booting. As of now, I've given up on the m.2 and have just bought a Samsung 850 EVO SSD but haven't cloned it yet because I'm still working out problems with the other drive. I used AOMEI partition software (another big mistake) and it failed to give me a partition. Then windows decided on reboot that the disk had all kinds of errors so it "repaired" it. It managed to give me the partition that AOMEI failed at. Cool, I thought until I discovered that windows totally screwed up the system in the process and wouldn't recognize the drive that contained my backups. So I had to do another windows install and re-install all my software. I had hoped to report success before now but it's been one problem after another. In the 25 some odd years I've been using computers, I've never had a machine give me so much grief. I've installed win7 at least 4 times on other laptops sans problems. Hopefully, as soon as I get all my software installed I'll be able to clone the drive to the Samsung EVO and be free of problems for a while as well as having a faster drive. Because everybody raves about how fast a m.2 PCIE drive is but I don't see it. My ASUS with a SATA SSD and a slower processor is faster than this GIGABYTE. I think this will be the last GIGABYTE I'll ever own.

Update 3

Success!! Finally! At this point, all I needed was a little more patience and the right software-- which was EaseUS and NOT AOMEI. Never again for that one. Don't know why it's so frequently recommended. Anyway, I was able to clone my mechanical storage drive to my new Samsung EVO 850 with no problem. Then I replaced the storage drive with the Samsung and with a bit more work and finagling, was able to clone from that to the Samsung M.2. I also discovered in the process of trying to update and get the right drivers for the system that what Xotic did was to use a crappy free driver updater program, giving me some crappy, incompatible drivers which was the original cause of the BSOD's, which in turn seemed to lead to no end of problems. Just a bad Windows installation on Xotic's part. Who'd a thought that they would be responsible for something like that. I thought those guys knew what they were doing. Anyway, it's been a long time coming, which I will chalk up to a super--albeit mind numbingly frustrating-- learning experience. BTW, I take back what I said about not seeing the big speed improvement with M.2 drives. Until today, mine just never worked properly. Now that it does, it's like warp speed. Really cool.

Solved, I guess. Thanks for being here for all of us.