If you try a USB keyboard does it work properly?

Yeah, external keyboard works. Actually, the built-in keyboard works well in Diagnostic page (enter by F12 during starting up) but not in BIOS page. I also tried hard reset. I'm feeling it is a driver issue (tried uninstall it already)

Hi @spikeyMushroom welcome to this free user to user Alienware laptop discussion forum. This is not Dell Support. 

If keyboard fully functional in Windows Safe Mode, but not in Windows Normal mode, it seems there is an application conflict. Updating the appropriate driver should reinstate keyboard function. 

Is System Restore function enabled? What is System Restore | Dell US 

Me too. Date: 6/25, 2022

update: they replaced the motherboard but now the audio is not working. such BAD manufacture. won't recommend anyone to ever buy dell products

Exact same issue here.  Ran through ePSA on my own and all the keys were registering in the test just not when you actually boot into windows.  Spent 2hrs on phone support yesterday and now they are sending out a new motherboard to be installed.

In all honesty, I think I'd rather just have a faulty keyboard since I use this laptop with a dock and external bluetooth keyboard anyways.  I've only had it 5months.  Very disheartening.

What other problems will arise after a motherboard replacement?  Stayed Tuned!