Since there are discussions about using USB drives on PS3 machines I won't write about that but you may want to ask a question like "How do I format a drive in Windows to work with my PS3?" (which is something you should google.)
Your post has no question.
I have an old hdd than i want to download movies to and watch them through the tv. I can do it with a flash drive b;ut when i do it with the hard drive through the playstation it comes up about can't read something to do about windows. Thought usb on tv doesn't show anything on the drive. Can watch on my computer. I format the hard drive before I put anything on it.