Can't mount/unmount CD/DVD.

[dthmnk]

I'm getting an error when I try to unmount my Windows XP SP3 CD from within VB. I'm running Ubuntu 9.10 (64bit) with Virtualbox 3.1.2. I also can't install the virtualbox additions ISO, as that too can't be mounted.
Here is the error I'm getting:

Unable to mount the -- on the machine Windows XP . Would you like to force mounting of this medium?
Could not mount the media/drive '/usr/share/virtualbox/VBoxGuestAdditions.iso' (VERR_DEV_IO_ERROR).


Result Code:
NS_ERROR_FAILURE (0x80004005)
Component:
Console
Interface:
IConsole {6375231a-c17c-464b-92cb-ae9e128d71c3}
Callee:
IMachine {99404f50-dd10-40d3-889b-dd2f79f1e95e}


It gives me an option to Cancel or Force mount, but force mount does nothing.

Any help is appreciated.

[Perryg]

Shut down the guest. Go to the storage section of the guest settings in the VBox program.
Click once on the CD/DVD and then on the right select empty in the drop down list.
Start the guest and then click on install guest additions.

[dthmnk]

Thank you for the fast response. I will try this once I get home.

Edit:

Thank you for the help, that solved my problem.