Back up your data, then, back it up AGAIN and AGAIN and AGAIN! And DO IT OFTEN!
I am so frustrated I could cry. To make a long story short, my quickbooks data file at work got corrupted, so I restored the back up. Unfortunately, I had not backed up far enough! For those of you out of the know, I have been in massive "clean up" mode of our financials because of some (OK, A LOT) of errors and issues from the time before me. We went through 4 bookkeepers in 6 months who all had their own systems and none of whom could make any sense of the original bookkeeper's (who was here for years) system. Needless to say, it has been a lot (months) of work, that I have been attempting to recreate for the last 3 weeks.
That said, I now back up every 2-3 days or more often if I've been doing a lot of work. So, GO BACK UP YOUR DATA RIGHT NOW!
You won't be sorry. And to think I knew better! Sigh.