It could mean a few things. One of the easier things to check is, like the messages says, the properties of the file you want to edit. Obviously you know where the image files are kept, so I won't tell you how to get there. Once you are looking at the image you want, RIGHT-click the file and go to PROPERTIES. Make sure there is not a check mark in READ ONLY. Then, open the file in Photoshop, make 1 small edit to the picture, and try to save it.If you get the same message, try clicking on FILE, and then SAVE AS. In that window, try saving it to you Windows Desktop. Does it save there, or do you still get the message?

It could also have to do with administrator privileges on the account you use for accessing your computer. That is a bit more involved and I really don't think we need to go down that avenue just yet.

Wow, it worked now because I putted it on my desktop.
Thank you very much.
*I'm a newbie in Photoshop. (STILL)*

You're welcome. Happy Modding.