I have tried several of the 'fixes' you have listed here. I also just bought SmartPC Fixer - still getting same error message!
HELP!!! I had two differnt printers, one an older DELL, the other a the HP Officejet H470, both had been working for over a year. Neither one are still listed in my printers file, and I can not reinstall them because I get this error message.
PLEASE HELP!