Expanding on the previous answer, it could be related to your drop in size, but also because your drive doesn’t come pre-formatted from Sandisk. I recently moved a 500GB HDD to my Ultra II 480 SSD. I actually did two drives. One into a MacBook Pro and one into an Asus VivoPC. The MBP easily upgraded with Time Machine. The VivoPC, however, wouldn’t read my new drive. After many attempts (using Disk Management, etc). So, I had to connect it to my Mac with an external enclosure, so I could format it with NTFS (using Tuxera). This allowed me to get it recognized on the Windows 10 VivoPC. Afterward, I was able to run EaseUs Todo Backup Free, which you can find at http://www.easeus.com/todo-backup-resource/clone-windows-10-hard-drive-to-new-computer-for-free.html. This allowed me to clone, and at the same time, it gave me new partition sizes. Asus defaults their machines to use 3 partitions on one drive, so this was very important to the cloning process from a larger drive to a smaller one.