Not so simple as it would seem.---Safety first.
If it is a completely new computer then please don't expect to be able simply to transfer the operating system from the old one.
The motherboard and any integrated things like sound and video systems will be different and the odds are that the transferred contents of the old HD will not run and may even corrupt what you have.
So install Windows to the new HD from the CD. Then the applications you want to use, (these will integrate properly as they should).
Finally you can transfer the data of every sort from the old to the new computer.
There are various ways to copy data as I'm sure you know, I just want you to save frustration that may occur if you simply clone evrything from the old PC to the new one's HD.