If I purchase Bitdefender Antivirus will I be able to re-install it on MY computer, without a back up disc?

In case of a system recover or something, will I be able to download the software again and just continue using it with my serial/key?

I'll need to pay 11$ more for a backup disc(optional) and their "explanation" confused me.

"

What is the Backup Disc?

If for any reason you need to reinstall our software (for example after a system crash), you can use the Backup CD/DVD to instantly have a clean install of the product. You can begin using the software immediately without the Backup Disc. The Disc can serve as a backup copy to download the software if you have to reinstall.

The Disc will be shipped by mail. You can purchase a Backup Disc only in conjunction with a product license.

The price for of the Backup Disc orders includes shipping & handling via:

* First Class Mail (USA Orders)

* Warensendung (orders sent to German addresses from within Germany)

* Kompaktbrief (orders sent to non-German European addresses from Germany)

* Air Mail (Rest of World Orders)

Average shipping time is 4 to 7 business days, but please allow up to 2 weeks for delivery to account for foreseen variances in production and shipping.

The Backup CD/DVD fees are not refundable and are not included in any refund policy.

We cannot change your shipping information after an order has been processed. If you have entered incorrect information, please call our Customer Service line at +31 88 000 0008 and we will submit a new order for you if possible."