Scrivener won't update

I’m having trouble updating to version 1.9.8.
The download works okay, the status bar filling up in no more time. I click on install,accept the legal stuff, click on the next buttons. Then, when I press on “start” Scrivener begins the install and I immediately stops and I get the message that there has been an error copying a file. The file in question seems to be the install program itself, and Scrivener wants to copy it to the file “eWebClient.dll” which lives in the Program Files directory. Then the key info: "destination is unwritable.:
I navigated to that file and confirmed that it’s attributes were NOT set to “Read only”. But the same error message persists.Any suggestions? My existing version is running but I;d like to get the new one,