Most people have at least experimented with Paint, the built-in--and rather basic--graphics painting application that comes with Windows. Although the best that many of us can do with Paint is to create Kindergarten-caliber artwork, there are actually skilled artists who use these types of programs. If you're one of them, mtPaint might be worth checking out. It's not the most intuitive program we've ever seen, but it packs a lot of useful features for both creating and editing works of digital art.
The basics of mtPaint's interface are fairly intuitive, with a color selector down the left side and a toolbar and menus across the top. But we were a bit puzzled when it came to accessing some of the program's features, such as its various brushes; they, along with the color editor and a really cool pattern selector, were located in an unmarked box of colored squares near the top of the interface. The program's lasso tool didn't work like any lasso tool we'd ever used before, and the same was true of the layering tool; the program actually created new layers out of what we thought were files that we had closed without saving. We also found it strange that when the pan window was open, we couldn't access any of the program's other tools; repeatedly opening and closing the pan window is a waste of time. That said, we did find mtPaint to have a pretty wide array of features, although none of them is particularly unique. Still, if you're willing to invest some time in reading its extremely thorough documentation and getting acquainted with its idiosyncrasies, we could see mtPaint being very useful.
mtPaint installs and uninstalls without issues.