If you want to use your digital photo frame as a secondary computer monitor, you may well be able to do it. Several manufacturers have recently introduced photo frames with the ability to also serve as monitors. If you have one of these models, the process for turning it into a monitor is quite simple.
Use a USB cord to connect the frame to an open USB port on the CPU.
Check that the computer has recognised that a new device has been added. Your usual desktop background should now be showing in the photo frame.
Move your cursor off the edge of your primary monitor screen. The cursor should now appear on the other screen. This allows you to have one application open in one monitor, while you work in another application in the other.