Thanks guys for the suggestions. I looked at slidedog and I think that will be useful. I will install it in one of our kiosks and run the "closed" sign to see how it works.
To "A Guy":
The OS I"m running is a regular Windows 7 pc. It's not running in "Kiosk" mode. We have a website that is accessed via google, where it takes us to the software that runs the application. The Kiosk doesn't turn "off" at 9:30pm, it stays on all night. I just need it to have a sign appear that states we are closed. The kiosk is used for customer's to retrieve their pictures and choose different backgrounds. They can then email those pictures to themselves(gmail, hotmail, etc) or use any social website(facebook, twitter, etc) to post their picture. It runs similar to the space needle in seattle washington(if you ever been there).
I wouldn't need to mess with the lock screen background image because it would never lock.
Pretty much this is how it works.
They customer purchases a ticket, takes a picture(free picture included with the ticket), we print out a picture receipt where the customer takes it to our GeO-deck(560 feet above ground) and approaches one of our Kiosks. He/she scans the picture receipt and their picture pops up. They then choose a background of their choice(we have 6 different backgrounds) and email it to themselves.
