GeeWally,
MS Paint will open and crop the pictures, but it will not convert them to a compressed JPG format used for the internet. BMP files are way to large to use over the interntet. If you compare the same picture in JPG format and BMP format you will see what I mean.
I use Irfanview and I have a few other photo editors. Irfanview is easy and quick to use if you want to crop, tweek and convert a screen shot.
Gunner