What Files You Can Safely Delete to Free Up Space

Updated 2026-09-26

The drive is nearly full, you have opened a folder full of things you do not recognise, and the cursor is hovering over the delete key. The question is always the same one: will this break something?

That worry is the reason most people give up and buy a bigger drive instead. So this page answers it directly - not with a vague "delete temporary files", but with a list of what is safe, a list of what is not, and the one rule that tells them apart.

Quick Answer

The safe things are the ones Windows made for itself: temporary files, caches, leftovers from updates, error reports, thumbnails. Windows creates them again whenever it needs them, so removing them costs you nothing.

The unsafe things are the ones somebody meant to keep: your own files, and the folders belonging to Windows and to installed programs.

If you would rather not judge each item yourself, skip to the safest way - Windows has a built-in tool that only offers you the safe categories in the first place.

The One Rule That Sorts Everything

Every file on your drive was put there by somebody: by you, by a program, or by Windows.

Windows constantly writes files for its own convenience - a copy of an update it is about to install, a preview image so a folder opens faster, a note about a program that crashed. These are working notes. Windows does not expect them to survive, and it writes new ones when it needs them.

Working notes are safe to remove. Anything meant to be kept is not.

That single distinction covers almost every decision below. When you are unsure about a file, the useful question is not "is this important?" but "who made this, and were they planning to keep it?"

Safe to Delete

All of these are working notes. None of them will be missed.

Temporary files. Leftovers from installations, updates and programs that closed badly.

1. Click Start, type storage and open Storage settings
2. Click Temporary files
3. Tick the categories you want and click Remove files

The Recycle Bin. Worth saying plainly, because it surprises people: files in the Recycle Bin still take up the same space they did before. Deleting something only frees space once the bin is emptied.

Windows Update leftovers. After an update installs, the installation files stay behind. They are often several gigabytes and they do nothing.

Delivery Optimization files. Pieces of updates Windows kept so it could share them with other computers on your network. Safe to clear.

Thumbnails. Small preview pictures Windows makes for your photos and videos. Delete them and folders will open slightly slower once, while Windows makes them again.

Error reports. Notes about programs that crashed, kept in case they were sent to Microsoft. Once they are days old they serve no purpose.

Browser cache. Copies of pages and images your browser saved to load sites faster. Clearing it signs you out of nothing and loses no bookmarks - pages simply load fresh the first time.

Old installers in your Downloads folder. The setup files you already used. The program is installed; the installer is a spare copy you can download again if you ever need it.

Programs you no longer use. Not by deleting their folder - see the section at the end - but properly:

1. Click Start, type apps and open Installed apps (called Apps & features in Windows 10)
2. Sort by Size to see the heaviest first
3. Use the three dots next to an app and choose Uninstall

Never Delete These by Hand

These are not "be careful" items. They are the ones that cause the evenings people write about on forums afterwards.

• Anything inside C:\Windows, and especially C:\Windows\System32. This is Windows itself.
• C:\Program Files and C:\Program Files (x86). These are the installed programs.
• The AppData folder (inside your user folder). It looks like junk and is not: your program settings, saved logins, browser profiles and game saves live here.
• Drivers, .dll files, and anything to do with starting or recovering Windows. A missing .dll is the cause of a whole family of errors - our guide on the vcruntime140.dll error shows what that looks like from the other side.
• A program's own folder. Deleting it does not uninstall the program, and it frees less than you expect. More on this below.
• Your own files in Documents, Desktop, Pictures, Videos or OneDrive - obviously, but it is worth checking what is in a folder before you decide it is rubbish.

The Grey Area: It Depends

Four things sit in between. They are safe to delete, but only once you know what you are giving up.

The Downloads folder. Windows treats it as temporary, you probably do not. Look through it first - for most people it is the single biggest easy win on the drive, and for a few people it holds the only copy of something.

Your previous version of Windows. After an upgrade, the old version is kept in a folder called Windows.old so you can go back to it. It is usually enormous. Microsoft keeps it for 10 days and then removes it automatically, and its own guide to freeing up drive space is blunt about the trade: delete it and going back to your old version is no longer possible, and that cannot be undone.

System restore points. Snapshots that let Windows roll back to an earlier state. Deleting them frees real space and removes your safety net at the same time. Keep at least the most recent one.

The hibernation file. A file the size of your memory, holding what was open when the computer hibernated. Turning hibernation off reclaims all of it - and you lose hibernation, which on a laptop is a genuine loss.

The Safest Way to Do All of This at Once

Everything above can be done in one place, with Windows deciding what is safe instead of you.

1. Click Start, type storage and open Storage settings
2. Click Cleanup recommendations
3. Work through the sections: Temporary files, Large or unused files, Files synced to the cloud and Unused apps
4. Tick what you want to remove and click Clean up in each section

The point of this screen is that it does not offer you anything dangerous. Windows chooses the categories.

For the older tool, which still finds things the Settings screen does not:

1. Click Start, type disk cleanup and open it
2. Choose drive C:
3. Click Clean up system files - this is the part most people never press, and it is where the update leftovers appear
4. Tick the categories and click OK

Our step-by-step walkthrough of the whole process is in the guide on cleaning up Windows safely.

One More Thing Most People Forget

Dragging a program's folder to the Recycle Bin does not uninstall it.

A modern Windows program is not one folder. Installing it scatters pieces across the system: registry entries, settings in AppData, shared components, scheduled tasks, sometimes a background service. Delete the visible folder and all of that stays behind - and Windows still believes the program is installed, which is why it may keep appearing in menus and in the list of installed apps.

You also free less space than you hoped, because a fair share of it was never in that folder.

Uninstalling properly, through Installed apps, hands the job to the program's own uninstaller, which knows where its own pieces are.

If the drive is still full after all this, the next question is not what to delete but what is eating the space in the first place. Our guide on checking the drive itself covers the case where the problem turns out not to be files at all.

Final Thoughts

Almost everything people are afraid to delete is either completely safe or completely off limits, and very little sits in between.

Working notes that Windows wrote for itself: go ahead. Things somebody meant to keep: leave them. When a file falls outside both, the honest answer is to find out what it is before deciding - not to delete it and hope.

And if that sounds like more judgement than you want to exercise on a Tuesday evening, the Cleanup recommendations screen was built exactly for that. It only ever offers you the safe pile.