The only difference between using a 2.5" drive and using a 3.5" drive is the physical mounting of the drive. You have some other issue.
Of course, the drive could be deader than a doornail, either due to defect or damage taken from your mobo or power supply. You ruled that out by putting it in the notebook; that's a good experiment.
If your mobo won't read either of two known good HDDs, then it.s a motherboard or controller problem. I'll bet you a quarter that it won't recognize 3.5" drives, either.
On further examination, I don't see a step where you did a Windows install. It looks like you took the HDD out of a notebook and just tried to boot it in the new build. Is this the case? Are there two HDDs in the notebook? Is it possible that you moved the non-bootable one?
With no CD/DVD drive, how do you install the OS?