I had a drive not show up on the desktop recently. It did this for the better part of the morning, then after some restarts etc, it showed up again. I've ordered a replacement and will replace it soon. While I was searching for a way to replace the files on the drive, while the drive wasn't showing up, I looked in Time Machine, but the drive didn't show up in past iterations in Time Machine. Once I got the drive to show up on desktop, it again appeared in Time Machine. My question is, shouldn't Time Machine be a picture of what your setup was at times in the past? Shouldn't I have been able to see that drive looking back a day or so or more? If not, I don't get it. If I drive goes down, how do I restore files from it if I can't see it in Time Machine?