Is there a utility that will record whatever I am playing on my computer, as I am playing it?

Most computers has the capability to record whatever it is that's playing on the desktop.

Open up the control panel, then double click on Sounds and Audio Devices. On device volume, click on advanced. The master volume window comes out. Click on Options>Properties and another window should come out. Click on the "recording" radio button, and on "Show the following volume controls" be sure to check a Stereo mixer checkbox (if you can't find it, then there's no other way to do it). Click OK and on under the Stereo Mixer control, there's a checkbox saying "Select". Check it, and turn the volume up a little, and open Start>All Programs>Accessories>Entertainment>Sound Recorder.

Then try playing anything on your computer, you should be able to record the sound in Sound Recorder.

Since you say 'playing' is it a game ?

Then there is a program called ' FRAPS ' that will, when you load it and touch a key of your choice, record the game you are playing and allow you to play it back later as a movie file.

Do a search on FRAPS and you'll find it.

Won't record windows movements or music playing but will make a movie of any 'game' you are 'playing'

Sarge

Camtasia will turn what happens on your screen into a video.