Hi again Pat,
I tried to install the downloaded program as administrator, as you suggested. I wasn't asked for my administrator password and the result was the same. Access denied. See below.
I had also done something earlier I should have done from the start. I do full backups to my external HD, using Acronis, so I did a full disc recovery. My last backup was a couple of days before the trouble started and the recovery process restored my PC to how it was before the troubles, so I have no reason to believe that there is now anything wrong with my Temp folder.
I did expect the recovery operation to also restore my administrator privileges, but it didn't. That problem must be embedded in my PC somehow, and that is preventing me for opening some of my files as well as not being able to install programs or print PDF documents.
Something I also need clarification on. When you talk of my administrator password, the only password I know is my logon password. Are we talking of the same thing? I can't see how that can be the administrator password as, as you know, it is quite possible to remove that password and still logon to the PC without being requested for a password. If I had to create an administrator password when I first set up my PC I have to admit to not being able to remember that or find any record of it.
Barry