One of us here is a Protel 99 SE user, and has developed a strange problem on his Acer laptop, running Windows XP. The program seems to startup, and shows its splash screen for a few seconds, but then no program window appears.
Protel has a Client99SE taskbar button (and it's also on the Task Manager list). If the button is selected it says you can Minimize, but Restore is greyed out. If you go ahead and minimize it, Minimize is greyed out and the Restore option is available, but clicking on that does not reveal a program window.
If you start the program by clicking on a .pcb file, for example, the splash screen is up for a longer time (while it's loading the file), but still no visible program window after the spash screen closes.
So it seems the program is running, but won't show a work screen.
Removing and reinstalling Protel 99 SE didn't fix the problem. Removing Altium Designer 6, which had been installed earlier, didn't fix the problem.