I still could not change them properly, so I found a way around this problem. If you have HP printer/scanner programs that will not install or leftover files that will not delete because you 'don't have permission' - look up how to change file access permissions for those folders and files.
I nearly rolled back today because of this, but found an answer. Windows 10 had somehow messed with my file permissions, and a number of files were affected. I uninstalled everything, but there were still some HP files and directories hanging on. No consecutive scanned filenames or folders, no multiple photo-detect.
I kept getting the 'scanner already in use' error. I tried everything in the thread to no avail. Well, I had a similar problem but needed a different solution. Business PCs, Workstations and Point of Sale Systems.Printer Wireless, Networking & Internet.DesignJet, Large Format Printers & Digital Press.Printing Errors or Lights & Stuck Print Jobs.Notebook Hardware and Upgrade Questions.