Want to root Using windows which is on VirtualBox.How do i make it recognise the fone when phone is off?
If you have the ADB drivers on Ubuntu, try performing the tasks of installing busybox and su manually as detailed here - http://androidforums.com/a52-all-things-root/586982-how-root-any-android-device-manually.html

The author has used Nautilus on Ubuntu to perform the requisite tasks. YMMV, though upon reading through the thread.

As a workaround, perhaps you could use the root methods detailed in the relevant XDA thread(s) on a Windows machine.