I hope this helps, I cant go into much more detail, the info pasted below came from a customer that fixed this issue on his own.
"I fixed the problem I was having with the PC Wallboard. For whatever reason, after I installed the PC Wallboard, two .dll files needed to start the PC Wallboard application only had administrative permissions set on them, preventing me from starting the APP as a regular user. The names of the two files are iccsplash.dll and QPRO32.dll, they both reside in the c:\%systemroot%\system32 folder or c:\windows\system32 folder. To ensure they are able to use the application unimpeded, I added each user to the Power Users local group on their respective PC and then added that group to have modify permissions on those files. We also could have just added the users group to have write or modify permissions to those files and it would have also worked".