I am running Windows XP Home on a Dim 8250.  For some time now I have lost the ability to view all the items (applications,processes,performance,users,networking) that use to display when I hit control,alt,delete.  I am however able to view a task folder telling me what is running, and a icon shows up on my taskbar indicating the CPU usage. How can I get back to where everything is displayed again?    I have looked in the Windows cd and Dell cd but I can't locate anything that will help me reinstall it.