Does anyone know if this is a system preference? I am working from a mac where I can't open anything on the desktop with a double-click. I have to open a program to oen the file. THANKS!
Open Applications->Utilities->Disk Utility and "Repair Permissions". If this doesn't help then go to USR->YourUserName->Library->Preferences and delete the file com.apple.finder.plist. After that log out and log back in. Then redo you finder's Preferences. This should help.
Less likely, in system perferences, is a setting for double click speed, and perhaps it is set for a long delay. This is less likely the problem, although worth checking out.