Macbook keeps getting "stuck" - please help!

[HelpCourtneyPlz]

Last night I was playing around on the internet and I saw the "Software Update" bouncing in my dock. I ignored it for a little while to finish what I was doing, and then I closed my Safari browser and began the update. Once the update was finished and my Macbook restarted, my Macbook started to make funny noises (and still is). The sound is coming from the core of the Macbook and sounds like a sort of fluttering noise. Not only this, but my Macbook lags now, in a sense that it continuously gets "stuck" - for instance, while I type this, the "Waiting" cursor flashes and I can't see any words that I type until the Macbook gets "unstuck" -- basically very intense lag.

Please ANY help on what to do would be great. I basically can't do anything with my Macbook getting stuck every 5 minutes.

I am on a Macbook (obviously), with Leopard OSX installed. I don't remember (I don't think I looked at) what the System Update was for.

[jcaru]

Did you try doing another software update and see if there are anymore updates to do. If it's a firmware update you need to following the instructions and the let the computer do the update. It would help if you knew what update you were trying to do.