yes on windows, using MS Paint is the best thing to do!. Ofcourse, there are hundreds of options.
And on linux, using convert command at the shell is the best thing to do.
Yes that is exactly what she can do use paint or use photoshop... either way she can get the results.. Just wondering how did she end up with a bmp? did she have her picture on a secure website and downloaded her pic by right clicking?
If you can`t/don`t want to shell out for a flavor of Photoshop, GIMP (GNU Image Manipulation Program) is a great free alternative for this kind of stuff.
You can download it from www.gimp.org.