BF2S Forums System Restore, do you leave it on?

I just use it just incase I get a major error like blue screen and my computer will just not boot up no matter what, sometimes system restore gives you enough to get you back into your computer to back up anything you wanna keep before you just reformat.
I almost lost a whole year of me and my wifes pictures from a bad system error. From the day we met to a year later, that would have been bad. But the worst thing that can really happen, if you can't get back in is you would have to buy a new hard drive and transfer your old file over to the new.

I turn it off. The one or two times I've tired it, it's never worked. Plus, it whores hard drive space.

Not to mention that if I get to the point where I've fucked something up enough to have to use it, then I'm better off just formatting and starting over.