It would be nice to tell us about your system an version and about any error message you get. Use exact version numbers, please. Saying "the latest" may or may not be true and may mislead those trying to get answers for your problem!
Did you have Photoshop installed prior to this?
What is the exact Photoshop version you are trying to install? You know that there is Photoshop and Photoshop Elements?
ABAMBO | Hard- and Software Engineer | Photographer