I studied the Virtualbox documentation regarding using a raw partition for my Linux (guest) installation in VirtualBox. So, I do not need to reboot the system when I am want to switch from Windows (actually XP-32 in the future Win 7-64) to Linux. For performance reasons I want to use a native partiton for my Linux guest system to bypass Windows' file system when accessing the hard disk in the guest system. For security reasons it is not advised to work with administrator privileges, even if many Windows users do so. Normally that's no problem with VirtualBox.
Windows does not allow native access to the whole harddisk or some of its partitions without administrative privileges, which is in necessary for a secure architecture. So the problem is, that I am not able to gather native access to a raw partition except when running VirtualBox with administrative privileges.
Is there a solution that Virtualbox systemdrivers can grant access to special native partitions when running it under user privileges?