Cannot Access The Specific Device Or Path

Whenever I click on some , but not all, of my shortcuts on desktop,, I will get a pop-up window that says, " Windows cannot access the specific device, path, or file. You may not have the appropriate permission to acceess this item ." A couple of shortcuts I can open & they work fine. My e mail program, Outlook Express, & Mailwasher, will not work at all. I, also, just noticed that I get the same message window, whenever I try to open some functuions of my computer, such as uninstall programs,,, system restore, & MANY others.