First of all I really don't think you have to be concerned about changing any setting in your BIOS. The likelihood is that the SATA controller is already set to AHCI.
You should have no problem using a disk-cloning program to clone the contents of your present HDD to your new Samsung SSD provided...
1. Your present system is without problems. The HDD boots without incident and functions effectively and you would have no qualms in migrating the entire system over to your new SSD, and,
2. The disk-capacity of the SSD is sufficient to contain the total contents of your HDD.
Given those caveats you can go ahead with the disk-cloning operation.
Fortunately you have a Samsung SSD. The Data Migration program that's bundled with the SSD is an excellent disk-cloning program to use with your system. We've used the program more than a dozen times and it has worked flawlessly.
Here's a rundown re using the SDM program:
(Before you begin ensure that the only drives that are connected in the system are the source & destination drives, i.e., your HDD & SSD. Uninstall any other storage devices that may be connected such as a flash drive, USB external HDD, etc.)
1. With both your HDD & SSD connected boot the system. The system will, of course, boot to the HDD's Win 7 OS.
2. Install the Samsung Data Migration program on the HDD.
3. Access the program and click Start.
4. The Source Disk (your HDD) and the Target Disk (your SSD) will be identified.
5. Click Start.
6. Click Yes when the confirmation message appears.
7. The disk-cloning process will begin. It can be a lengthy process depending upon the amount of data that's being cloned.
8. When the cloning process has successfully completed a message will appear to that effect.
9. Click Quit, then Shut Down.
10. After the system has been shut down disconnect the HDD from the system and boot to the SSD. Assuming all is well ensure that your new SSD boot drive is connected to the first SATA connector on the motherboard which will be designated either SATA 0 or SATA 1. It will probably be the same SATA connector the HDD was connected to. The HDD can now be connected to any following SATA connector.
Work with the new SSD for a while to determine no problems exist. Then you can do what yur want with the HDD which I assume you'll be installing as a secondary drive for backup/storage purposes.
Good luck.