What if my laptop crashes and I need to buy a new laptop, or reinstall Windows?
 

 
On the My Account page accessible here you should see a "Products" menu item.  That will give you a list of all the products you have bought and their download links.
 
The store has been updated recently so if it doesn't, or anything is missing, use the Feedback option on the same page to report the issue to Cakewalk and they'll fix it for you.

There is no fee to download a product again.

 I would also point out that the Cakewalk licensing agreements allow for you to install licensed products onto additional computers, BUT you are only allowed to 'run' a single copy at any one time.
 
Bob Bone

What you should do on ALL downloaded software products is to download the package and save it to a DVD or a spare hard drive. That way, you don't need to download it again....
 
Also write the unlock key and serial numbers on the disk or sleeve for added convenience.  All my stuff is on disk in one way or the other.
 
But.....failing that, you can always download it again at no cost if you are a customer.

What Guitarhacker says...
Even if Cakewalk secures your purchases, many other maybe don't. So always save all your downloaded purcahes on DVD, backup HDD or a memory stick.

+1 on saving downloaded installation files.
 
This has made life much easier many times in the past for me.
 
Bob Bone