Your hard drive just failed. What have you lost?
The odds are that this is an event that you will experience - perhaps multiple times. I find it hard to believe the number of people not backing up their important files - especially their pictures. I was talking to someone last night that had not made a backup in over 8 months.
I minimally recommend that you have three copies of all of your files. One copy lives on your computer's hard drive, one resides on an external backup hard drive that remains at your home/office and another copy on an external backup hard drive that is taken somewhere offsite - perhaps to a family member's house. My backup plan is much more thorough than this strategy, but again, I said "minimally recommend".
Remember that a backup plan is not a one time event. You MUST backup regularly - including rotating a fresh copy to the offsite storage location.
If your hard drive failed right now, would you lose anything important to you?
If your backup plan is not all it should be, here is a deal for you
has the small Western Digital My Passport Essential SE 1 TB USB 3.0/2.0 Ultra Portable External Hard Drive (Black)
on sale for only $79.99 shipped. I have over a dozen of these - they work great.