I called the store where I bought it and talked with one of their tech people. I told him that after one week my operating disc was so full that the two programs that I had downloaded (a paint shop program and a video studio program) would not work. I told him, as suggested by blogger Gary Denness in a comment here, that the computer was suffering from "bloatware", an excess of unwanted, garbage programs. Although the tech guy did not agree with that, he showed me how to uninstall unwanted programs. (There were a bunch of them! Yes, definitely "bloatware". ) He also showed me how to change the settings so that any pictures, documents, etc., that I add would go into the much larger storage disc instead of the crowded operating disc. He said that to make my printer operate normally, I would have to go to the manufacturer's website and download software. (I still have to do that.)
Another problem that I had encountered was that the Windows Media Player... which had worked perfectly fine on my old computer... would play music but not videos. Again, Gary Denness came to the rescue, and told me that I would have to download something called a "codec" to remedy that. He even gave me a website from where I could download it. I did that, and now the media player is working. Thanks, Gary!
I am keeping my fingers crossed that the truce between my computer and me will hold.