Have you backed up your photos? If not, you are at risk. It isn't a matter of IF something will happen to your photos on your computer disk, but WHEN. Be sure you have a copy of your important files - images and other files.
In the "good old days" when you shot film, you had a backup. You had negatives and prints - assuming you knew where the negative was for each print (I'm probably missing about 25% of my negatives...). In the digital photo world, if the image file gets deleted or corrupted, or the hard drive crashes, or your computer is stolen, the files are gone.
External USB hard drive
Make a backup of all your files. Store it somewhere away from your computer. The software that came with your camera probably has a backup function. Use it. Back your images up to CD or DVD or another hard disk. Storage is cheap these days. An external hard drive in a case that plugs into your computer by USB cable can be had for under $100. That's cheap insurance!
I back my files up to an external hard drive that I can remove and store elsewhere. This external drive attaches to my computer by USB 2.0. (I also have another drive that connects by Firewire.) CDs and DVDs aren't all that reliable, so I don't trust them to be my only copy of my irreplaceable image files.
My rule of thumb is that I should always have at least two copies of my images. That means I never delete the photos from my flash card in my camera until I have loaded them all onto my computer and made a backup of those files. Within a short period of time (no more than a few days) I make a second backup to be stored away from the first, so that both copies are unlikely to be destroyed, lost or stolen at the same time. My second copy currently resides in a fire safe in my basement. I plan to augment that with an off-site copy. (Before I got the fire safe, my 2nd copy was stored in the trunk of my car.)