"The Windows 7 USB/DVD Download tool allows you to create a copy of your Windows 7 ISO file on a USB flash drive or a DVD. To create a bootable DVD or USB flash drive, download the ISO file and then run the Windows 7 USB/DVD Download tool. Once this is done, you can install Windows 7 directly from the USB flash drive or DVD. "
onthelimit1 refers to the COA, just in case you are unfamiliar with this abbreviation it is the Certificate of Authenticity click here that shows your copy of Windows is genuine. You should find it on the bottom of a laptop or on the back of a desktop. You will need the code from it when you do as Batch suggests as you install Windows 7 having downloaded the ISO file. You can burn an ISO file to a USB memory stick if you have one big enough.
Cameron. Your 'click here' is the download tool only - with that you will still have to purchase W7. If Batch's Digital River link is still working, you can download an ISO copy for free (make sure it is for the same version as you had fitted originally). Use the free ImgBurn to burn the ISO image.