The little red text above the reply tells me this is rather old, but I'm trolling and feel like helping out. So since this was never answered ...
To change the file format of a photo, you typically want an image editing software. If you want something that has a bunch of options and you can use to make animated .gifs and a bunch of cool paint functions, etc., etc. You want Photoshop CS
But for the purposes of just loading a picture and saving it from one format to the other. I'd recommend a simple free software such as
IrFanView . Just load the picture in, crop it or resize it if need be, then re-save it as a .jpg or w/e. (Note: May not support all file formats like .tiff , etc. I haven't used it in awhile).
