FastStone users can download Capture and use it for free for 30 days. A lifetime license is purchasable directly from their website, which will give you access to the software for as long as you need it.
After the download, just unzip it to get the exe file (installer). A zip (compressed) file that includes all the required files to run the application independently from any folder you dump it in. Major advantage is that you can carry it around on a memor
It allows you to easily capture and annotate anything on the screen including windows, objects, menus, full screen, rectangular / freehand / fixed regions as well as scrolling windows / web pages.