For those that say to back up, I couldn't agree more, I actually use an online back up service (costs me about $5.00 per month for unlimited storage) that is ALWAYS running in the background, as soon as I add new photos, they are backed up. In addition I now subscribe to Smugmug and I am working on getting all of my photos uploaded to there as a secondary backup for my photos at least. In addition, I am still working on doing DVD backups. Also, all of my data is on an external drive, so if there is ever an emergency, all I have to do is grab the drive and take it with me. I also am going to get an additional external hard drive and use that as a backup. I will not loose my dat, especially my pictures, I currently have about 25,500 pictures and I know some are missing, so they must be on a CD somewhere.
Oh, and also do not use your computer for anything, take it to a professional, as they can take the hard drive out and examine it with another computer, so that the swap file doesn't overwrite any data.