Windows 7 - Switching HDD for OS by keeping the configuration

Hi, I am buying a new HDD for my system, and my question is how can I copy the OS from the old HD to the new one by keeping the boot configuration/don't ruin the OS?
I believe that is possible, becuase I've heard of it years ago. I have a clean install of Windows 7, on another internal HD which I will be using to do this trick.
So if the MBR damages I can rebuild it easily, though I don't know about all the other stuff that may be stored on the system drive. Can you suggest me any softwares, that will make any exact copy of the HD? (I'd appreciate hearing from any personal experience) Maybe I can just copy the whole disk with explorer, then rebuild the MBR, but I'm unsure (eg. what will happen to fragmented files, will they be written like on the old disk, or they will be defragged during the copying and be copied 1 by 1)
Thanks SG

You can apply a Windows 7 backup image to a new HD.
Backup Complete Computer - Create an Image Backup
System Image Recovery
If it fails try free Macrium Reflect or Paragon 11.

If either HD is WD or Seagate you can use their free Acronis cloning apps to clone over the old to the new HD.
Seagate Acronis cloning free util
WD Acronis free cloning app

Be sure to select to copy/clone the MBR and Track 1.

If Win doesn't start once the source HD is removed, make sure it's marked Active and boot the Windows 7 DVD Repair console or Repair CD to Startup Repair - Run 3 Separate Times

Thank you, yes the new one is a caviar black so i will use the WD migration software.
Can I run it from the OS that I want to copy, or do i need to install it on my seconds Windows 7 os which is on a 3rd drive?

I would burn the WD Acronis boot disk to use to clone with only the source and target HD's plugged in.

Post back a screenshot of your maximized Disk Management drive map with listings so we can look over it to see potential problems. Tell us which drive will be cloned, and which you want to remain after cloning.

Use the Snipping Tool in Start Menu.

I hope I incuded everything

Been a while since I used it, but I seem to remember that Acronis True Image (the old name for Acronis Backup and Recovery) had a "clone disk" feature -- which is what you would want to use.

Just connect the second drive (the target) to your PC, boot from the Acronis CD, and clone your existing disk to the new one. When you swap disks, everything should then just work.

You might have to reactivate your new install since the disk serial numbers changed, or it might just reactivate for you.

I would plug the target HD for cloning into DISK0. Afterwards remove the source HD and plug Data into it's cable. Set the target HD as first HD to boot in BIOS setup, after DVD drive.

If Windows 7 will not boot on its own after specifying cloning of MBR and Track1, make sure it is marked Active and boot Windows 7 DVD Repair console or Repair CD to Startup Repair - Run 3 Separate Times

Hi, thank you all,
I have created bootable media with the Acronis software, and booted into it, but it doesn't see my HDDs, only the disk that it is running on.
I have done the same with EaseUs Disk Copy, boot, bang, nothing is visible at the HD section!?!?
I have resetted the BIOS, and I have the latest one, it can see the drives, windows can see the drives, what the hell is happening?

Any help would be greatly appreciated, this problem is extremely annoying.

I do not use Acronis or EaseUs.
Is there a option to load Sata Controller drivers?

Um, I've seen that in windows recovery but not here..
These two are pretty stragith forward, you can't do anything else than they are for.
I see only this screen with less options: