Where Windows keeps temporary files (%TEMP%, C:\Windows\Temp), what is safe to delete and the supported ways to clean them.
Temporary files are files that Windows and programs create while they work, such as unpacked installers, caches and intermediate data. The main locations are the user folder %TEMP% (C:\Users\<name>\AppData\Local\Temp) and C:\Windows\Temp. Most of them can be deleted safely once the program that created them has closed.
Programs are supposed to delete their temporary files, but crashes, interrupted installs and updates often leave them behind. Over months the folders can grow to several gigabytes.
Settings > System > Storage > Temporary files lists categories such as Temporary files, Windows Update Cleanup, Delivery Optimization files, Recycle Bin and Downloads with their sizes. Storage Sense can remove temporary files automatically.
Downloads and Recycle Bin also appear in that list: they contain your own files, so check them before ticking.
Files that a running program still uses cannot be deleted; Windows skips them. This is normal and does not mean the cleanup failed.
Note: Rain Cleaner shows each temporary-file category with its size and reason before cleaning.
Last updated: 2026-10-08
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