Backup is not the same as ghost. You will need to Image it.
The reason why it wouldn't work to just copy it goes like this.
When you install Windows and apps and everything the PC knows on which sector and which part of the sector the information is on. Copying and pasting it to another drive will not give you the same sector and and part fo the sector for the OS to operate correctly. So when you go to do anything. Click on the start menu or run a applicaiton you will get a error cause the information it is looking for is not where it was located alst time.
So it will take the PC 2x or even 3x longer to work out simple tasks and you will come back saying that the machine is utter slow now with a new drive.
Does that expalin it better why you can not just copy and paste it?
With a Image you take basically a snap shot of the drive as it is and the Image will be placed on the new drive exactly as it is now. Which will not cause any issues with the operation of the system.