Jim is wondering if he has a virus. He tried to erase old PDF files and folders and got an error that Windows couldn't. Leo says that some viruses can survive a format, but they're unusual, and are not easily accessible in folders on Windows. They're usually hiding in the Master Boot Record or in the memory of the video card. It's probably just a precautionary message.
Jim can repartition his hard drive and get rid of them. Would it be safe to move those PDF files to another drive? Leo says he can, as long as he keeps his Reader files patched. Since Adobe's Acrobat gets updated automatically now, he should be fine.