[SOLVED] Adding Ram -> Arch Linux Not Booting

Running Arch Linux, I have just added more memory from 16GB -> 32Gb. I added two more 8GB sticks into the free 2 slots I had. I have now have 4 of the same sticks in the 4 slots. On boot my BIOS (?) complained that the memory/cpu had changed, and to enter startup. ~32GB is present in the BIOS menu. On boot though, I get stuck on "loading initial ramdisk".

I got a bit spooked and so removed the two new sticks. Fortunately, the system still boots fine.

Any thoughts on what needs to be done to get the system to boot? Last time I changed memory the system booted fine so I wasn't expecting to run into issues.

Cheers