I have a Lenovo desktop with W8.1. Would like to make a Systems Image (File History etc.) to initiate it. Am trying to use a 128 PNY 3.0 USB flash drive which should be large enough. It is formatted as a NTFS drive but am getting an error message that indicates that this drive cannot be used for the Systems Image. Can someone explain why not and is there a solution? If I cannot use the W8.1 program for the systems image, is there a free app that will allow easy creation of an image?