Unable to mount VirtualBox Guest Additions as a guest (Win7 host)

Question

I keep getting this error dialog with an Unable to mount error E_FAIL ( 0x80004005 ) when I try to mount Guest Additions:

I tried the Force Unmount, but that just closes the dialog with no action taken. If I then reattempt to mount Guest Additions, I just get this same dialog box again. Any help would be greatly appreciated!

Answer 1

Finally, I figured it out. Here is how you get arount this. First, load Disk Utility and manually eject the disk in the CDROM, by clicking on the Eject button, after selecting the CDROM device. Then try to remount Guest Additions using the key combination Host + D and voila, Guest Additions should mount successfully.

Answer 2

I could not get the autorun to work, installed manually by doing:

cd /media/VBOXADDITIONS_4.2.4_81684/
sudo sh VBoxLinuxAdditions.run

Answer 3

I had to add one more step.

1. Unmount Volume
2. Eject
3. Rerun Install Guest Additions

Answer 4

Unmounting the volume on devices -> CD -> Remove disk from virutal drive

This will show the "Remove disk from Virtual drive" option as disabled on the same page once you clicked.

Then Press Host (Keyboard:Right Ctrl) + D i.e Host+D

This started working installing automatically on my Ubuntu screen.