I have Windows 7 Home edition on a new computer. My old drive is now configured as a USB drive. I would like to delete all unnecessary data and use it for backup. Windows 7 will not allow me to delete (or even see) all the files in the Windows XP directory, even though I am logged in as administrator. I have another drive which I would like to copy to the primary drive. There is about 20G of data on that drive, but Windows 7 will copy only about 5G. How can I resolve these issues?