Windows rarely runs out of space for a mysterious reason. A few categories account for most of it, and each has a safe way to check it. Use this page as the starting point and open the guide for the category you are looking at.
Space usually goes to a short list of things: apps and games, temporary files and caches, downloaded update data, the previous Windows installation after a big update, and your own large files such as videos. Knowing which category is largest tells you where to look.
Start with Settings → System → Storage, then look for large files and folders. Our guide on finding large files shows four built-in ways, including a read-only PowerShell command. Do this before deleting anything.
Temporary files, thumbnails and cached update data can be removed from Settings → System → Storage → Temporary files or with Disk Cleanup. Read each entry before ticking it. Downloads and the Recycle Bin deserve a look first, because they hold your own files.
Windows.old (the previous Windows installation) can be large but removing it ends the option to go back. The WinSxS folder looks huge in File Explorer but is mostly shared files; it should be cleaned with supported tools only. Windows Update Cleanup removes superseded update files. Each of these has its own guide with the trade-offs.
Before a major cleanup, make sure important files are backed up and that a restore point exists. Move large files you rarely use to an external drive instead of deleting them straight away.
Check Storage settings. Review large files. Check Downloads. Review Temporary files. Review Windows.old. Run Disk Cleanup. Check Windows Update Cleanup. Review apps by size. Back up first.
Rain Cleaner (Windows 10/11, 64-bit) shows what it found, with an explanation for each item, before it removes anything. The Free version has no ads; Pro has a free 14-day trial (no card). Everything on this page works with Windows alone - Rain Cleaner is just another workflow.
Last updated: 2026-10-03
Temporary files, thumbnails and cached update data are normally safe to remove. Downloads, the Recycle Bin and the previous Windows installation need a look first.
Open Settings → System → Storage, see which category is largest, and then read the guide for that category.
It gives Windows room to update and work. It does not by itself make the processor, graphics card or internet faster.
Built-in tools first, and what to check before you delete.
A practical order to check before you change anything.
A short, ordered checklist before you change anything.
Read the ID, understand it and search the maker's official page.
What each cleaner is built for, and who it fits.
What is safe to remove, and what needs a second look.
What it removes, what you lose, and when to use it.
Why it looks so big, and the safe ways to shrink it.
What it holds, what you lose, and the supported way to remove it.
What the cache is and how to clear it with Windows tools.
A sensible order for network, chipset, storage, graphics and more.
Add one driver or a whole folder from the command line.
Look first, back up, then remove - with Android's own tools.
Why they appear and how to remove them without losing a good shot.
Rain Cleaner: review before cleanup, free version, 14-day Pro trial.
Hash check, Defender scan and the SmartScreen steps.
How to report a security issue privately.
What we are working on now, next and later.
A safe order of checks: df, inodes, du, open deleted files, logs, packages and Docker.
Check the size, vacuum it once, and set a permanent limit.
Four built-in ways to see what is taking the space, before you delete anything.
Nine steps in a safe order, printable.
Backup, restore point, preview first, and what never to delete by hand.
What they are, how to shrink them safely and what not to touch.
Free, no account, no subscription. Windows 10 and 11.