Windows wont boot from new m.2

Aug 21, 2018
2
0
10
Hi there i ordered a new m.2 this christmas, (an intel 660p 1tb) to replace my old wd blue 1tb. i did all the standard stuff like back up my data and then i made a usb with windows 10 installation media. i rebooted my pc and began to install windows. keep in mind my wd blue still has windows installed. i installed windows and success. i installed all my personal data back to the new drive and everything. i had been using the new ssd for a few days and made a deal with my friend to sell my old hard drive. i needed to format it quickly to give it to him though and after windows had given me plenty of warnings that it could not format this drive, i stupidly decided to format it through the windows 10 installation process. i formatted it and all seemed well. i tried to boot into my ssd afterwards and was greeted with the error "no operating system was found. please disconnect all drives with no operating system"
... okay?
so i disconnected all the other drives (including the usb) and rebooted. now when i turn the pc on it goes straight to the bios. any attempts to boot from the bios send me right back to said bios. i was stumped. so i reinstalled windows on my wd blue and it worked. yay. i then used the easeus tool to rebuild the SSDs MBR and set it as active. i did that, rebooted and... nothing. same result. so i tried a fresh install of windows on the ssd... nothing. same result yet again. im really at a loss right now. any suggestions would be welcome.

system specs:
intel i5 8400
asus z370-a prime
trident z 3000mhz 16gb
msi rx480 4gb gaming x
and the aforementioned drives


EDIT
Theres been a development. I tried doing a fresh install of windows without the other drive connected and it boots properly. i will make another update if i run into anymore issues. i would still like to know what the causes of this were so that i can better understand this and be ready if i happen to screw up like this again so i would still like an answer from anyone kind enough.
 
Solution
Theres been a development. I tried doing a fresh install of windows without the other drive connected and it boots properly

This is how you are suppose to perform the M2 install ^ Otherwise it won't successfully boot.