(Parallels Desktop 9, latest version)

As per instructions, I switch to root:

$ su - root
$ whoami
root
$ echo $EUID
0

and then execute the installer:

$ cd /media/cdrom0
$ ./install

and I get this error:

sudo: unable to execute ./install: Permission denied

What? I'm root! What's with this? I double check to make sure the execute bit is set:

$ ls -lA | grep install$
-r-xr-xr-x 1 root root  17284 Oct 25 09:22 install

Yep. People online are saying that you need to drag the install script to the terminal after typing sudo. So I do that, and this command is what's formed:

$ sudo '/media/cdrom0/install'
sudo: unable to execute /media/cdrom0/install: Permission denied

What's the solution here?