I’ve been reading online lately about a number of cases where users have found their C:\Windows\Temp folder filling up with hundreds or thousands of files whose names start with AppXDeploymentServer or AppxErrorReport. Several users report tens to hundreds of gigabytes of such files piling up, to the point where system drives fill up completely. This Tenforums thread introduced me to the problem: Windows temp folder filling up quickly. But this SuperUser.com thread pointed me at possible causes and solutions: TEMP folder filling up with AppX files and canot [sic] be stopped.
First things first: In no case I could find (or think of) would deleting the contents of the C:\Windows\Temp folder cause irreparable harm to a Windows 10 system. If your drive is running low — or out — of disk space, it’s OK to whack these files. The initial AppX at the beginnings of the filenames lends strong credence to the SuperUser diagnosis that something wonky is going on with the App Server associated with the Windows Store. This kind of thing can happen when the Store Cache gets corrupted, or download status for updates doesn’t get reset following a successful download (as it should do). If you read the SuperUser article, it will point you at most of the key fixes worth trying. If you click through Setttings → Update & Security → Troubleshoot, however, you’ll also find a Windows Store Apps item that’s probably worth trying out as well.
Though the Troubleshooters — including the one for Windows Store Apps — don’t always cure all Win10 ills, they’re still worth trying anyway. Who knows? You might get lucky!
Another Temp Cleanup Strategry/Tool
In looking at the contents of the C:\Windows\Temp folder, I was also able to confirm that one of our recommended Admin Toolkit items will clean it up, too. That item is Josh Cell Software’s Uncleaner, which I covered here at Win10.Guru in January 2018, just after the site launched. After I ran it on a couple of test machines, the contents of that folder decreased from several hundred to five (5). Thus, you can run the tool to clean up the folder even before you diagnose causes and start working toward some kind of fix. Lord knows that when Windows starts filling up the C:\ drive without rhyme or reason, immediate clean-up is probably warranted.
Here’s hoping that nobody who reads this story gets hit with this particular Windows gotcha. But if you do, you should now have some ideas on what to do, and how to attempt one or more fixes.
Author: Ed Tittel
Ed Tittel is a 30-plus-year computer industry veteran. He’s a Princeton and multiple University of Texas graduate who’s worked in IT since 1981 when he started his first programming job. Over the past three decades he’s also worked as a manager, technical evangelist, consultant, trainer, and an expert witness. See his professional bio for all the details.