For specific usage questions, refer to the PS forum and by all means do provide more details. Nobody can help you based on such vague posts.
I'm moving this to the Photoshop forum.
Could you describe the issue more clearly, but giving some informations about your system (Mac, Pc, ram, etc.)
A screenshot might help also. It might pinpoint if you are, for instance, trying to move a locked layer, or the background layer.