Depending on what you're doing, there is GIMP, the Graphic Image Manipulation Program. Someone actually has done a "hack" that makes all of the menu items look and act like Photoshop.

As a non-profit, you may wish to try Open Office, which can save to Word format, but sometimes the formatting is off.

FYI, the State of Massachussetts has deemed non-open sourced proprietary file formats are not permitted any longer in State Government, as there is no guarantee that corporate owned file formats are going to be universally acceptable in the future. I.E. (no pun intendended... Microsoft could design to require licensing of the .doc format)

If you decide to go Linux (which none of these programs specifically require Linux, most have Windows binary versions...), you might find that things run faster. It does however require some more intermediate knowledge to setup and run.