Test the Motherboard Alignment
Test to see if the holes on your Motherboard line up correctly with the 8 Motherboard Standoffs you just screwed in.
Make sure you are wearing your Anti-Static Wrist Strap!
Gently take out the Motherboard from its Anti-Static bag, and lower it inside the case.
Use the Center Motherboard Standoff to align the Motherboard correctly.
Check to see if the remaining 8 holes on your Motherboard lines up with the 8 Standoffs.
Place the Motherboard back in its protective Anti-Static bag when done.