1. Your present Win 7 OS installed on the HDD boots & functions without any problems whatsoever, right? So there's no problem with the "source" disk, right?
2. You haven't by any chance installed that firmware update that was released by Samsung earlier this week for the 850 Pro, have you? Because if you have, all bets are off. That update has caused myriad problems for Samsung 850 users.
3. Can we assume that when you performed the disk-cloning operation the HDD was connected to the first SATA connector designated either SATA 0 or SATA 1 and the SSD connected to another appropriate SATA connector?
4. The Samsung "data-migration" software has proven to be quite reliable but stuff happens (including user error). Have you repeated the disk-cloning attempt? And you're reasonably certain you're correctly using that piece of software?
5. Anyway, if the Samsung program is still a "no-go" try a different disk-cloning program and let's see what happens. Try this Macrium Reflex Free program which is available at...
http://www.majorgeeks.com/files/details/macrium_reflect_free_edition.html
It's not my usual disk-cloning program (the one I use is a commercial program that costs $49.99) however I've used this Macrium program a number of times and it seemed to do the job fine as a one-shot disk-cloning program.
Some of the members of a local computer club I attend were interested in the program so I prepared these instructions as a handout for using the program:
Before opening the Macrium Reflex Free program and undertaking the disk-cloning operation close any open programs and remove or uninstall all storage devices, e.g, flash drives, other external USB devices, from the PC other than the source & destination disks that will be involved in the cloning operation. It is unnecessary to uninstall any other fixed HDD/SSDs.
The destination disk can be installed either as an internally-connected drive or as a USB external HDD/SSD.
1. With both the source & destination disks connected, boot to the source disk & open the Macrium Reflex Free program.
2. The opening window will reflect the two disks. The destination disk will be listed below the source disk. Both disks should be check-marked (default).
3. Click "Clone this disk".
4. On the next window click "Select a disk to clone to...". The destination disk should appear in the window.
5. Click on the graphic of the destination disk, then click Next.
6. The Clone Summary window will appear indicating that the source disk will be copied to the destination disk. Confirm that the correct source & destination disks have been noted.
7. Click Finish.
8. The Confirmation Overwrite window will appear requesting confirmation of the disk-cloning process. Again, ensure that the correct source & destination disks have been listed.
9. Click Continue...
10. After the destination disk is successfully cloned ensure that it is connected to the motherboard's first SATA connector which will be designated either SATA 0 or SATA 1 depending upon the motherboard's designations. I'm assuming, of course, that the cloned disk is to serve as the PC's new boot drive.
Good luck.