Start by looking before you delete
Go to Settings > System > Storage. Microsoft says Storage settings show usage by category, including installed apps, temporary files, and system and reserved storage. Use that view to decide where to begin. If apps dominate, start with uninstalling. If it's "Temporary files", start with cleanup.
Don't assume a nearly full drive is the cause of every slowdown. Microsoft does say that low space can cause slower performance and trouble installing Windows updates. Some guides quote a "keep 10 to 20 percent free" rule, but I found no official Microsoft source for that figure. Treat it as a rough habit, not a requirement. Likewise, nobody can promise "tens of gigabytes" back. It depends on what's on your PC.
Windows 10 or Windows 11?
The menus are similar but not identical, so don't follow Windows 11 steps blindly on Windows 10. Cleanup recommendations are a Windows 11 feature, and Microsoft's Windows 10 guidance points to Disk Cleanup instead.
Windows 10 support also ended on October 14, 2025. Microsoft says Windows 10 PCs will still function, but technical support, feature updates and security updates are no longer provided. Consumer Extended Security Updates can cover eligible devices until October 12, 2027. The storage tips below still work on Windows 10, but a tidy drive doesn't change its support status.
1. Uninstall apps you recognize and no longer use
Open Settings > Apps. Windows 11 calls the list Installed apps, and Windows 10 calls it Apps & features. Sort by size, then uninstall what you no longer need.
- Start with finished games, trial software and bundled extras.
- Look up anything unfamiliar before removing it. Some entries are drivers or OEM utilities that your hardware relies on.
- On Windows 11, Cleanup recommendations also has an Unused apps category.
Game and app sizes vary widely, so don't expect a fixed saving.
2. Hunt down large personal files
File Explorer's search box has size filters. Type size: and Windows suggests named bands. Here the sources disagree, and the original guide's figures look wrong. It claimed that size:gigantic means files over 128 MB and size:huge means 16 to 128 MB. Those are the older Windows 7-era ranges. Several current guides for Windows 10 and 11 list different ranges:
| Filter | Range reported by current guides |
|---|---|
| Medium | 1 MB to 128 MB |
| Large | 128 MB to 1 GB |
| Huge | 1 GB to 4 GB |
| Gigantic | Over 4 GB |
One guide lists these as Medium (1 to 128 MB), Large (128 MB to 1 GB), Huge (1 to 4 GB), and Gigantic (over 4 GB). Other guides repeat the older bands. These ranges come from third-party tutorials, not Microsoft documentation, so I'd rather you avoid depending on the labels. Typing your own threshold is clearer. For example, size:>1GB lists everything over 1 GB, and size:>500MB works the same way. Sort the results by the Size column in Details view.
Searching a whole drive can be slow. Searching a specific folder such as Videos or Downloads is quicker.
Microsoft's own approach is simpler. Open the Videos, Music, Pictures and Downloads folders, switch to Details view, and sort by size. Those folders usually hold the biggest personal files.
Never delete anything in the Windows or Program Files folders. Leave system files like pagefile.sys and hiberfil.sys alone too.
3. Clear temporary files, carefully
Option A: Settings. Go to Settings > System > Storage > Temporary files. Windows lists categories. Read each one before you click Remove files.
- The list can include your Downloads folder or Recycle Bin, which may hold things you want.
- If you upgraded Windows recently, Previous Windows Installation(s) may appear. Microsoft warns that deleting it removes the option to go back to the earlier version, and that this can't be undone.
- Microsoft says that option only appears within 10 days of an upgrade. After that, Windows removes it on its own.
Option B: Disk Cleanup. Search Start for "Disk Cleanup," pick a drive, and review the categories. Select Clean up system files for more options. Microsoft notes that Downloaded Program Files, Temporary Internet Files and Thumbnails are ticked by default, so untick any you want to keep.
Windows 11 only: Cleanup recommendations. It's under Settings > System > Storage. It groups suggestions into Temporary files, Large or unused files, Files synced to the cloud, and Unused apps. It also shows the space you'll save before you confirm.
If space keeps vanishing
Microsoft documents one odd case. After using Cleanup recommendations or Disk Cleanup, you may still get Low Disk Space errors. The Temp folder can fill with Microsoft Store application (.appx) files. Microsoft's fix is to reset the Store, clear the Store cache, and run the Windows Update troubleshooter.
4. Tidy Downloads and the Recycle Bin
Sort Downloads by size or date, delete what you don't need, and move keepers into Documents or Pictures. Deleted files still use space until you empty the Recycle Bin. Right-click it and choose Empty Recycle Bin. Emptying it makes recovery much harder, so check first.
Storage Sense: automation with caveats
Storage Sense is available on Windows 10 and 11. Microsoft says:
- It's off by default, but Windows may turn it on after a low-space event and notify you.
- With default settings, it runs when the device is low on space and cleans unnecessary temporary files.
- Recycle Bin content is deleted after a time. Your Downloads folder and OneDrive or other cloud content aren't touched unless you configure it.
- It only works on the system drive, usually C:. Other drives are handled under Advanced storage settings.
- It won't run unless you're signed in and online for more than 10 minutes.
- Settings apply per user.
If you enable automatic Downloads cleanup, understand that it deletes files you haven't opened for the time period you set. That's convenient, but it suits only people who don't leave important files in Downloads.
5. Move files off the drive, with care
OneDrive Files On-Demand
Files On-Demand keeps placeholders on your PC and stores the full file in the cloud. Microsoft's documentation says:
- A blue cloud icon marks an online-only file, which takes no local space. Opening it downloads it. You can't open online-only files without an internet connection.
- Right-click a file and choose Free up space to turn it back into online-only. Choose Always keep on this device to keep it available offline.
- It requires Windows 10 version 1709 or later. From OneDrive build 23.066 it's on by default.
- Check Settings > Sync and back up > Advanced settings if you need to turn it on.
The important trap: Free up space is not the same as Delete. Microsoft says deleting an online-only file from your device deletes it from OneDrive on all devices and online. You can restore it from the OneDrive recycle bin for up to 30 days on personal accounts, or up to 93 days on work or school accounts.
Moving files out of your OneDrive folder is different again. Microsoft says they download to the new location and are removed from OneDrive.
Windows 11 can also make this automatic. Storage Sense can turn inactive OneDrive files online-only. Microsoft says that since Windows 11 version 22H2 the default period for OneDrive files is 30 days, if you've enabled that option. This doesn't delete anything, and files marked Always keep on this device are exempt.
External drives
Microsoft's advice is to move files you want to keep but rarely use to a USB drive or SD card. Copy them first, check that they open, and only then delete the originals. You can also change where new content is saved under Storage settings, so new files go to another drive.
Neither option is a full backup on its own. Keep a second copy of anything important.
Two more options Microsoft documents
- Compress the OS drive (Windows 10 guidance). Microsoft describes this as a way to gain room for important updates without deleting your data. Open This PC, right-click drive C:, choose Properties, and tick Compress this drive to save disk space. You can undo it later.
- Run a malware scan. Microsoft notes that malware can sometimes eat drive space. If you suspect an infection, use Windows Security.
If Windows says it needs more room for a feature update, Microsoft also describes using external storage to complete it.
A safe order of operations
- Check Storage to see what's using space.
- Empty the Recycle Bin after reviewing it.
- Run Cleanup recommendations (Windows 11) or Disk Cleanup (Windows 10).
- Uninstall apps you recognize and don't use.
- Review big personal files, and move rarely used ones to external storage or make them online-only.
- Turn on Storage Sense, and think hard before enabling automatic Downloads deletion.
Bottom line
The basic advice is sound: uninstall unused apps, find big files, clear temporary data, tidy Downloads, and offload what you rarely use. The riskiest steps are the irreversible ones: deleting the previous Windows installation, emptying the Recycle Bin, and deleting rather than freeing up space in OneDrive. Check each before you confirm. Results vary by PC, so don't expect a guaranteed speed boost or a fixed number of gigabytes.