There are settings in the menu on the left side of your screen or through the (file, edit,view etc.) that you can set file attributes so that only the original maker of a file can view or manipulate thos particular files. I found out the hard way and didn't know that setting was on and backed up my system on cd's then reinstalled xp on a diffrent hard drive then I couldn't even see the files on the cd's then for some reason I used my moms system running xp and I could see them so I coppied the files to a flash drive then put them on my updated computer. You might want to start with the attributes in the properties of that ext. HDD .