The case of the missing System Restore points

I received a terrific letter from reader George, who was having a problem with Windows' System Restore on his Dell Desktop.

Specifically, he noted that he was "losing" restore points, meaning they would disappear after he'd created them.

Before I read any further, I immediately thought, "Ah, I know what's happening here." By default (in Windows 7, anyway), Windows displays only a couple of the most recent restore points. What's easy to overlook is the option down below: Show more restore points.

Check that box and presto: a whole big list of them.

But, no, George hadn't simply overlooked that toggle switch. His restore points were gone, period, so he did the smart thing and visited various user forums in search of an answer. He quickly learned he wasn't the only one vexed by this problem. I'll let him explain what happened next. (I've edited portions of the letter for length and clarity.)

"On one of the forums, I just happened to notice that one of the responders asked if the questioner had any third-party disk defragmenters installed. I have Diskeeper 10, and it's set it to do automatic defragging, but that couldn't possibly be what’s eating up my restore points -- or could it?

"I disabled the automatic defragging feature in Diskeeper 10, set a few new restore points, and waited. In a couple days, I was surprised that I had several restore points still remaining in my System Restore Explorer. Today, with about eight restore points available, I decided to do a manual disk defrag using Diskeeper 10. You guessed it! Diskeeper deleted all of the restore points, or at least put them somewhere inaccessible to me."

That's some mighty impressive detective work, George -- couldn't have done it better myself. But I was curious, so I did a little investigative work of my own.

Sure enough, there's a body of anecdotal evidence suggesting that third-party defrag utilities can erase Windows System Restore saves. It appears to have something to do with Windows' Volume Snapshot Service (VSS), and if your defragger has a VSS compatibility mode (Diskeeper does), that might help to solve the problem.

Indeed, here's a snippet of related info from the Diskeeper 12 Professional product page:

"Volume Shadow Copy Service (VSS) Compatibility Mode
Diskeeper offers a VSS compatibility mode. This option minimizes growth of the VSS storage area caused by file movement, and it reduces the chances of older VSS and snapshots being purged."

Hope that helps, George!