For various audio/video reasons it was (is) very difficult for me (and I suspect other viewers) to get a clear understanding of the precise nature of the problem you're experiencing.
In any event, I take it the basic situation is that you have a 250 GB source disk, the contents of which you wish to clone to a 500 GB disk. Do I have this right?
Does the source disk boot without incident and function without problems? Assuming that it is so and the 500 GB disk is similarly non-defective, it sounds like a cut-and-dried disk-cloning operation should fill the bill for you.
Coincidentally I just sent the following post to for someone who was also having problems using a d-c (data migration) program. Perhaps it will be of some use to you...
It's not at all uncommon that these data-migration (disk-cloning) operations often go awry for one reason or another, especially for users who have had no experience using them. It's rather a shame that San Disk does not freely provide such a program designed for their own drives. C'est la vie.
There are a number of freely available d-c programs. Two of the more popular ones are...
EaseUS Todo Backup Free program
http://www.todo-backup.com/products/home/free-backup-so...
Macrium Reflect
http://www.macrium.com/reflectfree.aspx
Personally, I use a d-c program nearly exclusively for comprehensive backup purposes. But it's a commercial product ($49.99) and few users who are solely interested in a "one-shot" disk-cloning operation are interested in its purchase. However, there is a 30-day trial version available and you may want to give it a try since I can provide you with detailed directions as to how to use it, as follows...
1. Download/install the Casper Trial Edition v8 disk-cloning program from https://www.fssdev.com/products/casper/trial/
2. Before undertaking the disk-cloning operation close all open programs. (Generally you need not disable your anti-virus program). Ensure your destination drive - the proposed recipient of the clone - is properly connected in the system and ideally no other disks but the source & destination ones are connected in the system.
3. Double-click on the Casper 8.0 icon to open the program.
4. Click "Choose other options", then "Copy Drive" on the following window.
5. On the next window click "Perform a different copy".
6. The next window will list the drives connected in your system. The source (C:\) drive (the drive you will be cloning) will be highlighted. The System Reserved partition will be cloned to the destination disk as well. Click Next.
7. The next window will list your proposed destination disk - the recipient of the clone. If you have more than one potential destination disk currently connected in your system they will be listed as well. Ensure the disk you want to serve as the destination disk is highlighted. Click Next.
8. If the destination disk contains data the next window will indicate a warning that this data will be lost as a result of the disk-cloning operation. Click Next.
9. The next window gives the user an option to assign a name to the destination disk for future Casper disk-cloning operations involving that disk. If no name is desired uncheck the box. Click Next.
10. The next window reflects how the cloned data will be distributed on the destination disk. The default proportionate distribution option will suffice in nearly every case. Click Next.
11. A message may appear indicating that this Casper Trial Edition does not support "volume resizing" - basically user manipulation of partitions on the destination disk. This feature is available on the Casper commercial version. Click Continue.
12. On the final user screen click "Perform the copy now".
13. Exit from the program after receiving message that the disk-cloning operation was successful.
14. Now since you're cloning the contents of a 250 GB disk to a 500 GB disk, this trial version will create only a 500 GB partition on the destination disk to contain the total data contents of the 250 GB disk. (This is a limitation of the trial version. The commercial version would use (as the default) the entire disk-space of the destination disk for the cloned data contents.)
However, it's a simple matter following the d-c operation for you to use Disk Management to extend the 250 GB partition to encompass the entire disk-space of the 500 GB destination disk.
15. It's a good idea that following the d-c operation to temporarily disconnect your 250 GB source drive from the system and boot to the 500 GB drive as the only connected drive. After working with the cloned drive to ensure its "bootability" and problem-free operation; then you can reconnect the 250 GB disk to the system and do what you want with it.
Good luck whatever method you choose to use.