What I think is that you have performed a standard MBR install onto a machine who's BIOS is set to boot to UEFI Only and will likely need to be changed to UEFI and LEGACY before it can boot to the 2 TB drive install.
Most motherboard manufacturers publish their manuals on line in PDF format which can be downloaded from their website. Just go to ASUS support and navigate to your specific Motherboard Model Name and Number and it should be available to you.
Didn't you get a motherboard manual with this PC?
Who did the original install on the 1TB Seagate drive?
Have a way to change it? if you think this is make the problem..
I didn't get a motherboard manual with my PC.. I almost sure that not, or maybe i forgot, let me check.
I did, I installed the 1TB Seagate drive, I did same thing always, same way, same install, everything same..
But in the 2TB it isn't working from some reason..