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You can get it for windows.
I would still consider trying Linux because:
1) It is easier to discover,install, and update open source software if you use Linux. This is assuming you use a version of Linux (like Ubuntu) that has a good package manager.
2) If you are going to use unix/linux hosting it is a better test envirnment.
Definitely give the trial a shot and compare it to products like Gimp. I never liked Gimp's interface much.