Some help? (Computer savvy people please!)

Ok so i was trying to create a motivational poster. I made a collage on a ppt slide and then saved it in interchange format (jpeg). I then tried uploading it onto the motivational poster site but the final product cuts off part of the 最佳, 返回页首 and bottom of the collage picture. I tried shrinking the 照片 in picture manager but then when i 上传 it again to the website, the 照片 is just in worse quality and its still cut off.

Does anyone know how to resize the ppt slide picture so that it will fit properly? Unfortunately, i dont have photoshop...:(