Paint.net is a free
replacement for MSPaint.  MSPaint is convenient because available on every
Windows machine out there, but it’s extremely primitive and for those of us who
need a little bit more without requiring all the bells and whistles of
Photoshop, it’s not really an option.  After searching for a while, I
finally found Paint.net which, despite a few glitches on my machine, seems to be
very powerful while easy to use.