You can always use imaging software to make a backup of your working system. In the event of a crash, hardware failure or corrupted system, you can easily restore the backup....some let you do this outside of Windows.
I rarely use the restore disk or program that is put on your hard drive by your computer manufacturer. The restriction is that it only images your drive from the factory so you go right back to the beginning of when you turned on your computer for the very first time.
Check this link
for numerous freeware alternatives. Simply browse through the Hard Drive Utilities or the like.
I would personally recommend Acronis True Image. This is shareware but well worth the money. The thing I love about this program is that it allows you to make a bootable CD that you can carry with you and use on ANY computer (your friends, your work laptop, even one in an internet cafe) to make a complete system backup. The program is also very robust. For me, 5 out of 5 stars.
Get it here:http://www.acronis.com/homecomputing/products/trueimage/