Newbie activation question about adding a new primary HD

I read about it, but I am still confused on certain points. My actual HD works just fine, under Windows Pro7 32bits. I will add a new one that I want to install using my current W7 license.

Do I have to delete anything on my old one or disactivate it by a process unknown to me? Can I just proceed to install my new HD and just activate it even the second HD W7 is still under activation?

Txs in advance

If you are adding the new disk as a secondary drive, then you need do nothing at all.

If you are replacing the current drive with a new one, then teh procedure would depend on the type of installation you have.

If you bought the machine with WIndows pre-installed, you almost certainly have an OEM_SLP License.
If you bought Windows 7 separately from the computer, you (hopefully) have a Retail License - but this may be either an Upgrade or a Full retail license.

Machines form large manufacturers come pre-installed with an OEM_SLP Key which self-activates if other conditions are right. One of those conditions is that the proper Recovery Software is used for any reinstall.
If you don't have the proper Recovery software, then you can use a Retail disk for the reinstall, but must use the Key from teh COA sticker to be able to properly install and activate the installation - such activation may have to be by telephone.

With a Full Retail license, there is no problem - simply install with the appropriate Key and activate

With an Upgrade license, this requires that the machine holds a valid qualifying full license for Windows. To ensure this, Windows 7 Upgrade disks and Keys test for an existing installation on the hard drive. If it is not present, then the Key will be declared invalid, and the install blocked.