I recently upgraded from Windows Vista to Windows 7 Home Premium. When attempting to back up to an external hard drive with Windows back up in control panel it stops at about 20% completed and gives me the error code: 0x80070002. I have done a cmddsk /f/r on C drive. Didn't seem to help. I have a HP AMD quad with 8 gig of Ram and came with Vista home premium with free upgrade to windows 7 which I have done. Anybody know why i'm getting Windows 7 error code ox80070002 on backup? Any one knows what may be causing the error message? Kindly help me out. Thanks.