About a year ago, I was involved with a project to set up video signage. The project involved 6 displays, each to display its own content. Part of the initial assessment included the hardware and software necessary. The displays were easy, Samsung 42" LCD TVs. The content players were a little trickier, but the overall vote was to get mini player PCs (Intel-based), and install Windows on them because the entire company where they are located is all Windows based. I should have pushed a more stable operating system than Windows, but I did not.
I have taken some notes during the year. For one, if I could redo this project I would have strongly pursued a Linux-based player PC software package, if one is available. I have not done the homework but I would be willing to bet that there are some available, although they are probably going to be proprietary. In the case here, an enterprise grade solution was needed, so that multiple users could submit multiple content for each player, and each player would cache the content as well. I did some research at the time and did not find a true open source solution, unfortunately.
By running Windows, we have had to maintain the system more than we would prefer. At one point, Windows Update would pop up on the screen asking for a reboot. OK, no problem, adjust the group policy to allow the administrator to choose the time to install and set updates to install at 3 AM nightly. Then just yesterday, another player running Windows XP popped up with an error stating that the NTFS filesystem is corrupt and to run checkdisk. This was done, and the player was down for over an hour running checkdisk. Passers by would stop and watch the progress of checkdisk, very exciting content! And of course we would get questions from others of what happened to the regular content. But really, in an environment where the screen will be constantly displaying to many people, I would highly advise not using Windows, and choose a Linux-based solution. Linux is known to run for hundreds of days without a single reboot, popup errors, filesystem corruption, and the like that are common Windows problems. There are only 6 displays here, I cannot imagine having more displays and Windows players, 10, 20, or even more.