On a prebuilt system with the version of Windows already preinstalled you will have a problem when simply replacing the old one. If you are adding the new drive to see more drive space available leaving Windows intact on the original all you need to do is partition and format the new drive and use it for storage and backing up files there.
But without a full install disk for Windows you would have to bring it in to the dealer or a licensed repari shop to see Windows installed for you for a service fee. The other option is used commonly by those who build their own cases by simply buying an OEM copy for system builders of the version they plan to run.