If your Windows PC feels slower than it used to, takes longer to start, or keeps nagging you about low storage, junk files are usually part of the problem. Temporary files, leftover update data, cache folders, and old system logs quietly pile up over time. The good news is that you don’t need any third-party cleaner or “PC booster” to deal with them. Windows already includes everything you need.
I’ve cleaned dozens of Windows machines this way, from older laptops with tiny SSDs to newer systems that somehow still ran out of space. The process is boring, yes, but it works. And more importantly, it’s safe when you know exactly what you’re touching.
This guide shows you how to clean junk files on Windows without software, using only built-in tools and a few manual steps that Windows users often overlook.
What counts as junk files on Windows
Before deleting anything, it helps to understand what junk files actually are. These are not your documents, photos, or apps. Junk files are usually temporary or leftover data that Windows no longer needs but doesn’t automatically remove.
Common examples include temporary system files created during app installs, cached data from browsers and Windows itself, old Windows Update files, error logs, thumbnail caches, and files left behind after uninstalling programs. None of these are essential for daily use, but together they can eat several gigabytes of storage.
The key is knowing which areas are safe to clean and which ones to leave alone.
Using Windows Storage settings to remove junk files
The safest place to start is Windows’ own Storage settings. Microsoft built this specifically to help users free up space without breaking anything.
Open Settings, go to System, then Storage. After a few seconds, Windows scans your drive and shows a breakdown of what’s using space. This section is surprisingly accurate and often reveals large chunks of temporary files you didn’t realize existed.
Click on Temporary files. You’ll see categories like Windows Update Cleanup, Temporary files, Delivery Optimization files, and Recycle Bin content. In my experience, Windows Update Cleanup alone can take up multiple gigabytes after major updates.
Review the list carefully, then select the items you want to remove and confirm. Avoid anything labeled as Downloads unless you’re absolutely sure, since that folder often contains personal files.
This single step already clears a significant amount of junk for most users.
Turning on Storage Sense for automatic cleanup
Storage Sense is Windows built-in automation for cleaning junk files. It’s not aggressive, but it’s reliable.
Inside the same Storage settings page, enable Storage Sense. Once turned on, click into its settings and configure how often it runs. I usually set it to run monthly and allow it to delete temporary files and empty the Recycle Bin after 30 days.
Storage Sense doesn’t touch personal files unless you explicitly allow it. It mainly handles system junk, which makes it a good background safety net. Think of it as maintenance rather than a deep clean.
Clearing temporary files manually with the Temp folders
For a deeper clean, you can manually delete temporary files that Windows doesn’t always remove.
Press Windows key plus R, type temp, and press Enter. A folder opens filled with temporary files. Select everything and delete it. Some files may refuse to delete because they’re currently in use. That’s normal. Skip those.
Repeat the same process, but this time type %temp% in the Run box. This opens the user-specific temp folder, which often contains even more clutter.
I’ve seen systems recover several gigabytes just from these two folders, especially if they’ve been used for months without maintenance.
Emptying the Recycle Bin properly
This sounds obvious, but many people forget that deleting files doesn’t actually free up space until the Recycle Bin is emptied.
Right-click the Recycle Bin and choose Empty Recycle Bin. If you want to be more intentional, open it first and quickly scan for anything you might still need.
On shared or work computers, I’ve found the Recycle Bin alone holding old installers, video files, and screenshots that were never meant to stay there.
Cleaning up Windows Update leftovers with Disk Cleanup
Disk Cleanup is an older Windows tool, but it’s still incredibly useful.
Search for Disk Cleanup in the Start menu and run it as administrator. Select your system drive, usually C. After it scans, click Clean up system files. This second scan reveals deeper cleanup options, including old Windows installation files and update backups.
This is one of the few built-in tools that safely removes Windows Update leftovers, which can otherwise linger indefinitely. On systems that have been upgraded across versions, this step alone can free a surprising amount of space.
Removing old restore points you no longer need
System Restore points are useful, but they can quietly consume a lot of disk space.
Open Control Panel, search for System, then open System Protection. Select your system drive and click Configure. Here you can see how much space restore points are using.
If storage is tight, you can delete old restore points while keeping the most recent one. I usually do this after confirming the system is running well and doesn’t need to roll back.
Clearing browser cache without touching saved data
Browsers generate a lot of cache files over time. These files speed up browsing but can grow excessively, especially if you use multiple browsers.
Open your browser’s settings and clear cached images and files only. Do not clear saved passwords or form data unless you intend to.
This step won’t dramatically change performance, but it does reclaim space and can fix odd website loading issues. It’s also one of the safest cleanups you can do regularly.
Deleting leftover files from uninstalled programs
When you uninstall software, Windows often leaves behind configuration folders. These are usually stored in AppData.
Press Windows key plus R, type %appdata%, and press Enter. You’ll see folders for programs you no longer use. If you’re confident an app is fully uninstalled, its leftover folder can usually be deleted safely.
I recommend double-checking the app list in Settings before deleting anything here. When in doubt, leave it.
Checking for junk files after malware removal
If your PC previously had malware or adware, junk files may remain even after removal. These leftovers often sit in temp folders or obscure directories.
If you’ve ever followed a guide on How to Remove Malware from Windows PC, cleaning junk files afterward is an important final step. It helps clear residual data and ensures no broken temporary files are slowing things down.
When cleaning junk files isn’t enough
Sometimes cleaning junk files improves storage but not overall speed. In those cases, background startup items or system settings are usually the real issue.
If your PC still feels sluggish after cleanup, it may be worth reviewing broader performance tweaks like those that will be covered later in How to Speed Up Windows 10 Without Upgrading Hardware. Junk files are only one piece of the puzzle.
Common mistakes to avoid when cleaning junk files
One mistake I see often is deleting files blindly from the Windows folder. Don’t do that. Another is using random command-line scripts found online without understanding what they remove.
Avoid anything that promises “deep system cleaning” without explaining what’s being deleted. Built-in tools exist for a reason, and they’re designed to protect essential system files.
How often you should clean junk files
For most users, a light cleanup once a month is enough. Systems with limited storage or heavy usage benefit from more frequent checks.
I usually do a quick Storage settings cleanup monthly and a deeper Disk Cleanup every few months. This keeps storage usage predictable and prevents sudden “disk full” warnings.
Final thoughts
Cleaning junk files on Windows without software isn’t flashy, but it’s effective. You don’t need third-party tools, subscriptions, or risky cleaners to reclaim space and keep your system tidy. With a bit of awareness and occasional maintenance, Windows stays surprisingly manageable on its own.
Once you get into the habit, the process takes less than ten minutes and saves you from bigger problems later.