A man never knows his limitations unless he pushes the envelope.
A man who doesn't know what he is doing doesn't know his limitations either.
I doubt a dell system has a multiplier control. I have never seen an oem machine with one. If it did, it would not allow you to multiplier OC because INTEL locks the multiplier at the factory. And the Q6600 cant get anywhere near 5 Ghz on air. If it did, you would likelly blow out that stock Dell PSU.
Whatever you were on that night, don't work on your computer after using it next time!