Thanks to inveterate Windows wizard and toolsmith Sergey Tkachenko, I learned about a new cleanup method for Windows 8.1 Update installs to purge no-longer needed files in the wake of successful update installation (WARNING! If you follow this recipe, you will not be able to roll back from any updates previously installed). By now, almost everybody knows the technique of clicking the “Clean up system files” button in Windows’ Disk Cleanup utility to purge their systems of update files and info in the wake of a Service Pack or similar Windows Updates. This latest take on cleanup uses Microsoft’s Deployment Image Servicing and Management tool, implemented as dism.exe at the command line.
For those who’ve (a) successfully installed KB2919355 and its attendant patches and fixes and (b) are content to go forward under the new Update regime, here’s how to clean up after those updates are applied:
1. Launch an elevated command prompt (there are many ways to do this, but if you type Windows key-X and select Command Prompt (Admin) from the
resulting pop-up menu, that’s about as convenient as it gets in the Windows 8 world).
2. type the following line at the command prompt:
dism /Online /Cleanup-Image /StartComponentCleanup /ResetBase
This command will typically take a few minutes to complete (see following explanation for what it’s doing).
3. Exit command prompt
4. Using File Explorer, delete the contents of the C:\Windows\SoftwareDistribution\Download folder. Because you can’t roll back after the preceding DISM command, there’s no need to keep these files around any more.
What’s Going On in DISM?
According to the TechNet article “DISM Operating System Package Servicing Command-Line Option,” the /Cleanup-Image, /StartComponentCleanup, and /ResetBase options for DISM all fall in the category of switches designed to perform “cleanup or recovery operations on the [Windows] image,” where the /Online option tells DISM to work on the image of Windows 8 that’s currently running. In particular, here’s what’s up with the two final options in the list of DISM arguments:
- /StartComponentCleanup gets rid of any superseded components in the Windows component store (aka the often mysterious WinSXS folder), and thus also reduces the size of the component store itself.
- /ResetBase resets and reorganizes the remaining components in that store, and also helps to reduce the overall size of that component store, essentially by defragmenting its contents and eliminating slack or unused space therein.
The net result can be savings of 1-2 GB in the Windows partition on a typical Windows 8.1 Update install (YMMV in terms of actual numbers). There’s lots more interesting stuff you can do with DISM under the /Cleanup-Image category, so you’ll want to read further in the afore-cited TechNet article to learn more about what’s available to you.