Google Drive and Yosemite

I have an issue with Google Drive and Yosemite on a Macbook Air. This MBA has never had Google Drive installed on it. After I have downloaded GD, once I launch GD, I am getting this error message "The location selected for your Google Drive folder is not writeable". I never can finish the installation due to this message.

What is the easiest way to fix this problem without losing any files or folders?