Is it safe to delete Temp, SoftwareDistribution and Windows.old files?
Yes for Temp, the Recycle Bin and caches. Yes for SoftwareDistribution\Download when no update is pending. Never delete WinSxS or Installer by hand.
The short list
| Folder or item | Safe to clear? | Notes |
|---|---|---|
%TEMP% (your temp folder) | Yes | Skip files that are in use. Windows refuses to delete locked ones. Close Office and installers first. |
C:\Windows\Temp | Yes | Needs admin rights. Same rule for files in use. |
C:\Windows\SoftwareDistribution\Download | Yes, with care | Only when no update is downloading or waiting for a restart. See below. |
| Recycle Bin | Yes | Look first. Emptying it is permanent. |
| Thumbnail cache, shader caches, crash dumps | Yes | Windows and games rebuild them. |
C:\Windows\Windows.old | Yes, if you will not roll back | Remove it with Disk Cleanup, "Previous Windows installation(s)". After that you cannot go back to the old Windows version. |
C:\Windows\WinSxS, C:\Windows\Installer, System32 | No | Never delete by hand. Programs and Windows need them. |
Clearing the Windows Update download folder
The Download folder holds update files Windows has already fetched. If an update is half-downloaded or installed but waiting for a restart, deleting them can make the update fail and start again. Restart first, then run this in an admin terminal:
net stop wuauserv
net stop bits
del /q /f /s "C:\Windows\SoftwareDistribution\Download\*"
net start bits
net start wuauservWindows downloads any update it still needs again. Leave the neighbouring DataStore folder alone unless you are fixing a broken Windows Update, because it holds your update history.
Temp files: what could go wrong
- Open documents. Word and Excel keep files that start with
~$while a document is open. Delete them and you can lose autosave data. - Installers in progress. Setup programs unpack into temp. Clear it only when nothing is installing.
- Very new files. Only clear files older than a day. Anything fresher may belong to a running program.
The same thing in Trimmel
Trimmel lists each target with its size, then deletes only what you tick. It skips Office lock files, protects very recent files, refuses to clear update downloads when a restart is pending, and will not clean a root that looks like a drive or system folder.
Related guides
- How to move an installed program to another drive on Windows
- How to free up disk space on Windows 11 (and what is safe to delete)
- Which startup programs can you safely disable on Windows?
- How to update drivers safely on Windows (without a driver updater)
- Trimmel vs Microsoft PC Manager vs BleachBit
Clear junk without the guesswork
Trimmel lists each target with its size and removes only what you tick.
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