There seem to be some problems. Like I said, something like this happened back when I was using 4.0.6.
I hope the VM was turned off. You cannot uncheck those boxes unless the VBox machine is turned off.
You also need to install the extension when all machines are turned off.
Which version of Virtualbox are you using?
Are there any errors or warinings from within VirtualBox?
File -> Preferences -> extensions:
In this example VirtualBox 4.1.12 + extension pack 4.1.12 is used.
The versions have to match to assure best compatibility.
I recommend the latest version (by the time of writing: 4.1.16 for both packages)
A clean reinstallation can help if nothing else worked:
- remove the currently installed extension pack
- remove (uninstall) VirtualBox
****important---> if you allready used a couple of olders VirtualBox installs on your system (dating back from version 4.0.X or 4.1 beta ...) this step is recommended:
- go to your Windows directory in system32 and search for *vbox* (some old left-over VirtualBox drivers are here) and remove all the found ones that say vbox (this last step has to be executed properly and not deleting something else, be careful).
If you're still not sure of this workaround post some info about the VBox and the extensions you're using.
Regards
Hopachi