Here is my PSA for the day. PLEASE back up your data. I have dealt with multiple people this week alone who have had their hard drives crashed. To my amazement NOTHING was backed up. They lost photos, videos, music, school work, business documents, etc. It is so unbelievably cheap to do so please do it.
Basic Rules of Backing up:
1) A file isn't safe unless it exists in at least 2 places.
2) Make sure you have a local and off-site backup. (local can be an external hard drive you copy files to, or dvds you burn, etc. An off-site back-up can either be a copy kept online with services like carbonite, or a hardrive/disks that you keep somewhere outside your home)
PLEASE BACK UP NOW.