Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
I suggest that you first of all, disconnect your printer from the computer.
Then, go to the printers list, select your HP 6830 if it shows up there, and remove it by clicking on the - button.
Then tell me what the MAC OS X version currently on your computer is - by looking at
apple menu - About This Mac
for the 10.X version number.
Instructions will continue once I have that information.