I recently replaced my old hard drive with a new hard drive and I noticed that when the old hard drive isn't connected, my computer fails to boot to Windows, even though Windows is installed on an SSD. I took a look at my disk management and noticed that there is an EFI partition on my old hard drive. Is this what is causing the issue? If this is the case, how do I make it so that my computer boots from the SSD, instead of through this recovery method?
That partition on the HDD is because Windows was installed when both drives were installed. Windows decided to put system files on the HDD and if you disconnect it you can't boot anymore. This is why people always recommend you install Windows with only the boot drive installed and all the other drives unplugged.
I will let someone in here tell you if you can move that partition to the SSD. Not too sure about that.
If you can't a reinstall of Windows on the SSD without the HDD plugged will be needed. Wait for some answers first before doing that in case you can fix it without reinstalling Windows.