Changes in Win10's Windows.old folder
Windows Secrets
Long-time subscriber Elaine Marmel wants to clean up her upgraded PC by clearing out the large Windows.old folder created by the upgrade. This is normally done by invoking Disk Cleanup/Clean Up System Files (info ), but she's concerned about the consequences of this irreversible action.
Her question leads to a discussion of recent and important changes in how Win10 handles the Windows.old folder.
"I admit, I'm chicken. I'm considering deleting my Windows.old folder, but I'd really like more information before I do so.
"I upgraded a Win7 installation to Windows 10 Pro in April. Three days later, it crashed and burned. No worries, I had images from both before and after the update. But I decided that the best choice was to totally reset Win10. While not as much fun as, say, going to a movie, it was more fun than a root canal.
"The best part of the experience: Once I finished reinstalling my software, I to end up with a delightfully running computer — seemingly faster than at any time previously! So, all in all, I'm a happy Win10 camper.
"I figured I'd wait and see what happened to Windows.old after 30 days, when the upgrade roll-back files were supposed to be cleaned out. Well, nothing happened; Windows.old folder is still there.
I truly believe I no longer need the folder, and I'd like to remove it. But some information out on the Internet implies that I'll not be able to reset Win10 if I remove Windows.old. I think that's wrong — it doesn't make sense that Microsoft would tie resetting a Wind10 PC to having the Windows.old folder available.
"So back to my question: When I use Disk Cleanup/Clean Up System Files, I get lots of choices. I'm trying to decide which ones I can select to delete or whether I can safely delete them all.
"I was hoping you might do an article that would discuss what these things are and what risks one runs letting Disk Cleanup/Clean Up System Files remove them. (And, yes, I promise I'll do an image backup before I run Disk Cleanup.) Thanks in advance!"
You're correct, Elaine; the original version of Win10 was designed to keep the large Windows.old folder, containing the upgrade's roll-back files, for about 30 days.
But Microsoft has recently changed the way it handles Win10 updates. The current Windows.old folder might also contain roll-back files for Win10's routine, new-style, cumulative updates.
Now, if you clean out the large, original Windows.old (or let Win10 do it for you after a month), a smaller Windows.old folder could remain — or reappear after the next routine cumulative update. In short, your Win10 system might always have a Windows.old folder!
This is a very recent change; I don't yet know if the cumulative update roll-back files automatically clean themselves out after a month.
I suspect not. In previous Windows versions, older update roll-back files never went away on their own. That's why Disk Cleanup/Clean up System Files was introduced — to let you optionally get rid of obsolete and superseded update files.
If your system is working properly, and if you make and retain frequent backups or images, then these roll-back files aren't needed. You can use Disk Cleanup/Clean Up System Files to remove everything offered, anytime you want
That's what I do!
For detailed info on cleaning out old update files, see the Jan. 9, 2014, LangaList Plus, "Clean out obsolete, space-consuming update files." That article discusses Win8, Win7, Vista and XP; Win10's options are essentially identical to Win8's.