How to share files on Virtualbox with Windows as a guest? [duplicate]

Possible Duplicate:
How can i share the host Ubuntu machine desktop to guest Windows machine

I read this but the instructions were for 10.04 and does not apply in my case.

For 12.04+

The instructions in the link you provided are basically the same for 12.04. The menu are not the same and depend if you are running Gnome, Unity or something else but you can do it from command line with:

sudo adduser <your-user> vboxusers

Create the Ubuntu folder you want to share.

On the virtualbox part, it's the same: install virtualbox guest additions (from virtualbox menu inside the VM) and from the same virtualbox menu inside the VM, you can use the Shared Folder option to add the folder you created on the Ubuntu host.