The fastest way to see how much storage you have left

Open File Explorer (the folder icon on your taskbar), right-click on This PC in the left sidebar, and select Properties. You will see a pie chart showing your total storage and how much is in use. This takes about 10 seconds and tells you when ready whether you are running low.

If you are using Windows 11, you can also go to Settings > System > Storage to see the same information in a cleaner layout. This view also breaks down storage by category — apps, documents, pictures, videos, and temporary files — so you can see at a glance which type of content is taking up the most room.

On a Mac, click the Apple menu, select About This Mac, then click the Storage tab. You will see a horizontal bar showing how much space each type of file is using.

Key Takeaways

  • Right-click This PC in File Explorer and select Properties to see your total storage and how much is used in seconds.
  • Windows 11's Settings > System > Storage breaks down what is using space by category so you can find the biggest offenders.
  • Storage Sense in Windows can automatically delete temporary files and old downloads to free up space without your intervention.
  • If a single folder is taking up unexpected space, right-click it, select Properties, and Windows will calculate its total size.

Understanding storage types on your PC

Your PC has one main storage drive, usually called C: on Windows or Macintosh HD on a Mac. Some computers have a second drive, often labeled D: or E:. Each drive has its own total capacity and its own amount of free space. When you check storage, you are checking how much room is left on the drive where your operating system lives — usually C: — because that is the one that matters for your computer's performance.

If you have an external drive plugged in, it shows up as a separate drive in File Explorer. External drives do not affect your PC's performance the way your main drive does, so running low on an external drive is less urgent than running low on C:.

Finding which folders and files are using the most space

Once you know you are running low on storage, the next step is finding out what is taking up room. Right-click any folder in File Explorer, select Properties, and Windows will scan the folder and show you its total size. This works for your Documents folder, Downloads folder, or any other folder you suspect is large.

For a more detailed breakdown, use Disk Usage Analyzer (built into Windows 10 and 11). Go to Settings > System > Storage and scroll down to see categories like Apps & features, Documents, Pictures, and Videos. Click any category to see which individual items are largest. This is faster than checking folders one by one.

On a Mac, use Finder > Applications > Utilities > Disk Utility, then select your drive and click First Aid to see a detailed breakdown. Alternatively, third-party tools like DaisyDisk or OmniDiskSweeper show a visual map of what is using space, though these are not free.

How to free up storage without losing files you need

Your Downloads folder is usually the safest place to start. Most files there are installers or documents you no longer need. Open File Explorer, go to Downloads, sort by date modified, and delete anything older than a few months. You can also check your Recycle Bin (on Windows) or Trash (on Mac) — files there still take up space until you empty it.

Temporary files and cache are another source of wasted space. In Windows 11, go to Settings > System > Storage and click Temporary files. Windows will show you what can be safely deleted — old update files, temporary internet files, and cache from apps. Check the boxes next to what you want to remove and click Delete files. This usually frees up several gigabytes with no risk to your programs or documents.

If you have old video or photo files you do not use, consider moving them to an external drive or cloud storage like OneDrive or Google Drive. This keeps them safe but removes them from your main drive. Do not delete files you are unsure about — move them first, then delete after you confirm you do not need them.

Using Storage Sense to automatically manage space

Windows 10 and 11 include a feature called Storage Sense that can automatically delete temporary files and old downloads without you having to do it manually. Go to Settings > System > Storage and toggle Storage Sense on. You can then set it to run daily, weekly, or monthly.

Storage Sense will delete files in your Recycle Bin after 30 days (you can change this), remove temporary files, and clear the Downloads folder of files older than a set number of days. You can customize what it deletes and how often. This is safe because it only removes files that are genuinely temporary — it will not touch your documents, photos, or installed programs.

What to do if your storage is critically low

If you have less than 10 percent of your drive free, your PC will slow down noticeably because Windows needs space to create temporary files while running programs. Do not wait until you hit zero — start freeing space now.

Start with the steps above: empty your Recycle Bin, delete old downloads, and run Storage Sense. If that does not free up enough space, check your Documents, Pictures, and Videos folders for large files or old backups you can move to external storage. If you have a lot of installed programs you do not use, go to Settings > Apps > Apps & features and uninstall them — this can free up significant space.

If you are still running low after all this, you may need to upgrade your drive. This is a job for a technician — do not attempt it yourself unless you are experienced with opening your PC. A local computer repair shop can install a larger drive and transfer your files for you.

Checking storage on external drives and USB devices

External drives and USB flash drives work the same way as your main drive. Plug them in, open File Explorer, right-click the drive, and select Properties to see how much space is used and how much is free. You can delete files from an external drive the same way you delete them from your main drive — right-click and select Delete.

If an external drive is running low, the process is the same: find the largest files, move or delete what you do not need, and empty the Recycle Bin. External drives are less critical than your main drive, so running low on one will not slow down your PC — but it will prevent you from backing up new files or storing new media.

Frequently Asked Questions

Why is my PC running slow when I still have storage space left?

Slowness is usually not about total storage — it is about having less than 10 percent free. Windows needs that free space to create temporary files while running programs. If you have 20 percent free but your PC is slow, the problem is likely something else, like too many programs running at startup or a full hard drive that is failing. Check your startup programs in Settings > Apps > Startup.

Is it safe to delete files from the Windows folder or System32?

No. Never delete anything from Windows, System32, or Program Files unless you are following specific instructions from Microsoft or a technician. Deleting system files will break your PC. Stick to your Downloads, Documents, Pictures, and Videos folders, plus the Recycle Bin and temporary files.

What is the difference between storage and RAM?

Storage is the space where your files, programs, and operating system live permanently. RAM is temporary memory your PC uses while running programs. They are separate. Running low on storage slows your PC down; running low on RAM makes programs crash. You check storage in File Explorer or Settings. You check RAM in Task Manager under the Performance tab.

Can I move my installed programs to an external drive to free up space?

Some programs can be moved, but it is not straightforward. The safest way is to uninstall the program from Settings > Apps > Apps & features, then reinstall it on the external drive if the installer allows it. Most programs expect to be on your main drive and may not work correctly from an external one. For large files like videos or photos, use external storage instead.

How often should I check my storage?

Check it once a month if you read files regularly, or whenever your PC starts feeling slow. If you use Storage Sense, you can check less often because it handles cleanup automatically. If you do not read much or mostly use cloud services like OneDrive, you may only need to check a few times a year.