On each of my Windows 7 installs, I make a primary formatted partition to store a backup image made by Win7 Backup IMaging. Then I copy that image to an external drive in case of HDD failure.
This is how it is done:
Type "backup" in the start box. In the Backup Center choose "Create a Backup Image"
If you would like to make a recovery partition to store the image, then choose DVD option to get the size. Using Disk Management, format a primary partition on another HDD unless you only have one.
Now return to the Create a Backup Image utility and choose Drive option and it will locate that partition (since it is formatted Primary) as available to save the Image to. In about 20 minutes you will have your backup Image stored there, and it will then offer to make you a bootable Repair Disk with the same Repair Console as is on your Win7 Installer.
Then copy your Image to an external drive so that if your HDD fails the image can be applied to a replacement HDD. I keep each of my backup images in a folder for its computer, then place that image in the root of the drive for auto-detection when I need to reimage.
You will never have to reinstall again. Just boot into the Win7 installer/repair disk Repair console and choose Recover Using an Image and it will detect the backup image, then reimage your HDD (or a replacement) flawlessly in 15 minutes.