One reason to purchase a Big Box Computer is the stuff which comes with it. You can make your own Recovery Media Kit (RMK), by using the procedures outlined in the Gateway documentation (also available on their website). When you create your own recovery kit, its only the cost of 3 blank dvds necessary to do the burn operation.
I like to get the real thing from the vendor. The prices range, typically from $10 to $49 (Acer Laptop RMK was the most expensive).
I keep this kit with the computer, until it is retired.
If you don't have a recovery media kit, then you may be forced to purchase another Microsoft Windows License and load it onto your computer.
My point was that for the small price of the purchase, it saves the larger purchase of a replacement OS, when your computer is down and dirty, which is typical when your hard drive fails.