I once used my notebook to help a friend test his Lexmark printer. After that the printer's software is always in my pc and there is no way to delete it. So I search in Registry and delete everyhing related to the Lexmark. The result turns out to be I lost all network printers I installed and I couldn't add printer anymore. When I select "Add Printer", an error msg pops up saying "The operation couldn't be completed". I guess I messed up sth in the registry, but I'm not sure how to restore the functionality. Come on give me a hint.THx.