Thank you for your message.
Please try copying the installation file to your desktop and then install the Viewer from there.
In addition, please try selecting a different location on your computer as an installation folder for the Viewer.
Also, please let me know if this is the first time you're trying to install the Viewer or if it was installed on this machine before?
Besides, please verify if you're able to run Portable Viewer on the same machine? Portable Viewer is available for the download here
Looking forward to your reply.