ZoomIt is a Free Portable Application that can be used as a replacement Zoom Tool for Windows. This Screen Zooming Tool functions much like like the Mac OS X Zoom Tool but was designed for Windows XP and Vista Operating Systems. ZoomIt enables you to quickly Zoom in and out of a section of your screen using your Mouse wheel and can be enabled or disabled via any customize the key configuration. ZoomIt works great for video tutorials where you need to Zoom into a section of the screen to display.
Zooming Utility For Windows - ZoomIt
Authors Website: ZoomIt by Sysinternals
Download: You can grab this Screen Zoom Tool for Windows HERE