Most companies restrict your desktop experience for various reasons, one of the more annoying restrictions is having a screen saver popping up and locking your window. A simple way to bypass this is to start Windows Media Player, Hit Play on any song, select the continuous loop option, and finally mute the volume.
Very simple and elegant. WMP has a built in option under Player Preferences to stop the screen saver from loading. This option is generally turned on by default.
Of course you are circumventing your IT security measures, so use this with care, especially if you walk away from your desktop. always CTRL-ALT-DEL