I just had a friend lose 200 GB of data and come running to me asking for help. Unfortunately, the usual tricks didn’t work (Windows won’t even mount the drive).
Please please please backup your data. Buy an external hard drive and have it backup daily (or at least once a week).
I have my computer automatically backup to an external hard drive every night at 2am. I am working on a plan to burn all of my data to DVD’s and storing them off-site somewhere, to protect myself against the fire scenario.