You could run it, but it will most likely bog down that computer big time Photoshop can use up alot of memory. With only 1gb of RAM you’re going to be hard pressed for memory and the more intricate you get with file the worse it will be. Maybe if you are just doing photo retouching it would be OK, but once you start creating layers, adding fonts, and that sort of thing that computer is going to get real laggy and freeze up on you. If you are able to add more RAM to it then that’s what I would do.