PCLoupe

If you have a special need to zoom in to a particular portion of your desktop or any window you are using, you will find that PCLoupe is a great software tool to achieve this.

It is a free program that serves as a virtual magnifying glass that you can place anywhere on your screen, and that shows a zoomed image of the area surrounding your mouse.

This program does not come with the standard user interface. It only consists of a little window - which you can easily resize - where you can see the magnified version of a portion of your screen. The view will change as you move your mouse around, and closing this window will close the program completely. It also places an icon in your system tray area, which opens a menu from where you can carry out several actions, like hiding or showing the main window, increasing or decreasing the zoom degree (which can also be done by left- and right-clicking your mouse on the selected area) or keeping it 1/1 (no zoom). Another option will let you set the frequency with which the window's contents will be refreshed, or lock the window's image. Finally, you can choose to keep the window always on top, meaning that the zoomed window will be visible at all times, regardless of which window you are currently working with.

Due to its simplicity, this program is very light and consumes very low system resources.