OMG, it's enough to drive a person crazy, but I got it. After failing at the installlation several times I went to the temp file location where the installer was extracting the files to (in my case: "C:\users\Molly\AppData\Local\Temp\7zS45E6" - look for YOUR user name in place of "Molly") The folders begin with "7z" I believe, with varying numbers and letters after the 7z, but you can open them and see the 309g files within. I deleted ALL of the 7z temp FOLDERS - go back out of the files once you see that the 309g files are there and delete the WHOLE FOLDER, then I also emptied the recycle bin. I did not restart my computer because I was severely annoyed and impatient by this point. I then restarted the original installation package that I had downloaded from HP support. It extracted itself again and I was finally able to complete the installation.
Amazing and wonderful. Now I hope I can sleep off this tic that has developed in my left eye ;)