Access denied

I have recently installed Trados starter version, however when I try to generate a preview of the document, I get an error telling me that access to the "local/temp/SDLtempFileManager" file is denied. I have looked at that file and seen that the file is on read-only preventing modification of the contents (necessary for generating a preview), and have tried to change it, but when I click "apply" and "ok", the file remains on read-only. How can this be fixed? Thanks