I recently downloaded R-Drive 4.7 trial version to run tests to decide whether or not this program could be used here at the law firm I work at. I created an image of my entire hard drive onto an external hard drive, then I proceeded to make a disk-to-disk copy of this image onto another external hard drive. Both external hard drives are identical in storage space and the assumption was that they would have the same amount of free space after the images were stored on each of them. However, (F:) hard drive appears to have 3 GB more available space that (E:) hard drive. Upon reviewing the devices' properties, they have the exact same number of files. What is the problem?