Can't find him?

Go to his monitor, look to the left, there is a terminal on a wall, access this terminal and it opens a hidden door next to said terminal. There will be another terminal next to an elevator, access this terminal and go through the door, and inside will be a final terminal to open Mr. Houses Cryogenic Chamber.

Thanks do I have to kill him what happens if I disable him?

That very much depends on whether you've met Yes Man yet...

Spoilers follow.

Getting to and killing Mr. House has to be the single most anti-climatic event in the history of gaming. Click terminal 1, click terminal 2, click elevator, click chamber, shoot and he's dead. I went in there armed to the teeth with Pulse Grenades, Pulse Mines, the Pulse Gun, heavy weapons, lots of AP ammo and a healthy stock of consumeables. I was expecting to fight through a factory'ish basemant level, numerous gun turrets and all kinds of robots and security installations. I was quite disappointed. Finding him all shriveled in that chamber was cool, but it would be so much sweeter if you had to work for it.

I can't disable him only kill him? He says he'd rather be dead...