Peripheral

So, run that past me again...

If the monitor and keyboard are NOT working, what IS WORKING - how can you tell ?

It would help us a lot more if you could post with the specs for this system:

Motherboard, CPU, RAM, HDD, CD/DVD Drive, Monitor, any peripheral cards.

YOU can see what you've built, but WE don't know.

Have you updated your BIOS?
Have you checked your monitor and keyboard connections?
Have you plugged the computer into the wall socket?
Go back and re-check ALL of the connections.