Welcome screen won't go away!!!!!???

Hi everyone, new to the boards here, not new to Apple though. Proud employee of the Apple Store West Towne in Madison Wisconsin.

I just did the software update on my MacBook Pro that fixes the keyboard freezing problem (I never experienced the problem, I don't know why I did the update...) and it froze in the middle of shutting down after the update was complete. The dock wouldn't dissapear. So I had to power it down using the power button, and when I turned it back on the Welcome screen came up as if it was the first time I've turned on my computer. I can't get out of it, and if I just go through with the "re setting up of my mac" it will get to the end, think for a moment and then bring me back to the beginning Welcome screen yet again.

Tried restting the RAM, although I didn't think that would help anyway.

Anyone have any ideas??

Thanks.

Foster