IT WILL RUN ON WINDOWS-don't worry
Do you know Linux
it is a free operating system like windows
but windows is not free .
there are many programs running on Linux which are so so useful
and of course Free .
is one of them
it is like Photoshop
GIMP is Free . Photoshop is not free
you can know more about GIMP and see its features here
on that link " on right " you will find download link
if you want to download it directly from adwforums follow this link
GIMP is 15.6 MB