If you have a computer, and use it for anything important (and I qualify that word by saying that reading email, aimlessly surfing the internet, watching videos, and playing games are not what I mean as being important) and if you don't have some sort of back up plan for critical files (documents, photos, home movies, projects, and anything involved with making you some money) then you are a disaster waiting to happen.
I've been saved by my back-ups more than once, most recently last night. If you are a regular visitor to this blog, then you know I am an avid photographer. That means I have lots of photos stored on my computer, and I always back them up on external hard drives, and for the really important stuff, on DVDs. Long ago, I was burned by not having a back-up plan for important computer files, and when I did something dumb (which I seem to do more often these days) I lost everything due to an inability to boot my computer. So, I had to completely rebuild the system, albeit with none of the lost documents.
As I wrote above, attacks of "dumbness" lurk around every corner for me. What I did yesterday was to delete an important photo library/catalog file, which I incorrectly thought was outdated, and no longer needed. I have a habit of always trying to efficiently organize my document filing system (folders and subfolders) so when I see something I believe is no longer required, I dump it into the trash. Big mistake this time, because when I attempted to open Adobe Lightroom, which I use to both manage and process my photos, an alert message popped up telling me the program could not locate the necessary library/catalog file, and what would I like it to do. As panic slowly set in, I wondered if the file I'd deleted earlier in my attempt to better organize my folders, was the one Lightroom was searching for. It did not take long for me to confirm that this was the case. But then, I remembered that I had backed up those files on my external hard drive the day prior, and within a few minutes all was well again.
Take my advice, develop some sort of computer file back up system. If you are an Apple computer user, and have the latest operating system, then you are in luck because you have Time Machine always available (assuming you use it) to back up your entire hard drive to an external hard drive on a set schedule. It does this for you in the background. If you trash an important file, open up Time Machine, go back in time, find that file, and restore it. Easy fix. I'm not sure if Windows OS has a similar capability, but if it doesn't it should.