Can't download the pics

How much RAM and spare hard disk capacity do you have?

You download images that are open in Photoshop using the various Save facilities – File Save /Save As / Save a Copy (or for web use: File > Export).

For uploading it's: File > Open.

If you can't use any of these you may have a corrupt file or an incompatible format.

You may also have an issue with Photoshop that may be resolved by resetting the preferences back to the factory defaults which you can do under the Genera tab in Photoshop Settings.