can’t boot all the way

I cannot boot my computer past the point where it says verifying DMI data pool. It usualy goes straight to the splash screen from here. I cann enter setup but I can’t even boot from a floppy disk. I had just upgraded the ram (DIMM) when this happened. I’ve placed the original back in and I’m still having the same problem. I’ve checked and rechecked all cables and connections.

Thanks