Ok dood... It's like this, Right now you are probably running Windows right? ok... If you go into your C: drive and start deleting files your PC will probably never boot again unless you reinstall windows.. with me so far? Ok... The Xbox is the same way, you have a c: drive that has all the files that the XBox "NEEDS" in order to work, if you damage or erase any of those files you will not be able to use your XBox, it will not boot up.. the same as with windows. With me still? ok.. A virtual C: drive is a FAKE C: Drive that the XBox uses instead of the REAL one.. It's a copy.... That way if something happens to the files on the "FAKE" c: drive your XBox will still be useable. Some games will attempt to "update" some of the files on the XBox's "REAL" C: drive and when this happens it ruins ANY softmod that you have installed and you usually cannot use your XBox unless you open it and do some stuff to your XBox's hard drive by connecting it to your PC. But with a "FAKE" C: drive exists those games do not modify the "REAL" C: drive, they modify the "FAKE" C: drive instead. Don't woory about it too much, just keep in mind that it's like running around with a "FAKE" twin that looks just like YOU.. If someone tries to kill you they actually hurt the "FAKE" you because the "FAKE" you has these powers that make the "REAL" you invisible to everyone.