If you click the Add Printer Button in Windows 7 nothing happens.
I rebooted computer, still the same
I stopped and restarted the Spooler, still the same
I stopped the Spooler; went to …\PRINTERS folder, folder was empty, restarted Spooler, still the same
I used Microsoft Fix It, after running it gave me the Add Printer button that ended with:
o There is a problem starting printui; A Dynamic link library (DLL) initialization routine failed.