Start by finding what's taking up space

Before you delete anything, you need to see what's actually on your drive. Windows and Mac both have built-in tools that show you which folders and files are using the most space. On Windows, right-click your C: drive, select Properties, and look at the pie chart — it shows you at a glance how much space is used and how much is free. On Mac, click the Apple menu, select About This Mac, then Storage — you'll see a colored bar breaking down what's taking room.

These overview tools tell you the category (Documents, Photos, Videos, Applications) but not the specific culprits. To dig deeper, use a disk analyzer. Windows includes Storage Sense (Settings > System > Storage), which lists your largest folders and lets you drill down into each one. Mac users can open Finder, select a drive, then use the File menu to sort by file size. Third-party tools like WizTree (Windows) or Disk Diag (Mac) are faster if you have hundreds of thousands of files, but the built-in tools work fine for most people.

Key Takeaways

  • Use your operating system's built-in storage tool to see which folders and file types are consuming the most space before you delete anything.
  • Downloads folders, old backup files, and temporary system files are usually safe to clear and often hold gigabytes of space.
  • Move large files like video projects, photo libraries, and old documents to external drives or cloud storage instead of deleting them permanently.
  • Empty your Recycle Bin or Trash after deleting files, because deleted files still occupy space until the bin is cleared.
  • Uninstall programs you no longer use through Settings or Control Panel, not by dragging them to Trash, to remove all associated files.

Clear your Downloads folder and temporary files

Your Downloads folder is often the easiest place to recover gigabytes. Most people read installers, PDFs, and images they never look at again. Open your Downloads folder, sort by date modified, and delete anything older than a few months — you can always re-read an installer if you need it. Be cautious with .exe or .msi files (Windows installers) and .dmg files (Mac installers) only if you're certain you won't reinstall that program.

Windows also accumulates temporary files in hidden system folders. Open Settings, go to System > Storage, and click Temporary Files. You'll see options to delete temporary files, recycle bin contents, and old Windows installations. Check the boxes for what you want to remove — temporary files and the recycle bin are always safe. Old Windows installations (from updates) can be deleted if your current version is running smoothly, but keep them if you're troubleshooting a recent update.

Mac users should empty the Trash first (right-click Trash, select Empty Trash), then check ~/Library/Caches and ~/Library/Logs — these hold process cache files that can be safely deleted. If you're not comfortable navigating hidden folders, use Finder's Storage tab to delete old language files and duplicate files that macOS identifies.

Move large files instead of deleting them

If your drive is full of video projects, photo libraries, or archived documents you might need someday, moving them to external storage is safer than deletion. A 2TB external hard drive costs $50 to $100 and gives you room to keep everything. Connect the drive, create a folder for each category (Videos, Photos, Archives), and drag your files there. Once the transfer finishes, verify the files are actually on the external drive before you delete them from your computer.

Cloud storage like Google Drive, OneDrive, or Dropbox works similarly but requires an internet connection to access your files. Google Drive and OneDrive offer 100GB to 1TB plans for $2 to $10 per month. The advantage is that your files sync across devices and you can access them from anywhere. The disadvantage is that large files (video projects, photo libraries with thousands of images) upload slowly and eat into your monthly data if you're on a limited connection.

For files you rarely need but want to keep, external storage is usually the better choice. For files you access regularly from multiple devices, cloud storage makes more sense. Many people use both — external drives for large archives, cloud storage for active projects.

Uninstall programs you don't use

Programs you installed and forgot about can occupy 500MB to several gigabytes each. On Windows, open Settings, go to Apps > Apps & Features, and scroll through the list. Click any program you don't recognize or no longer use, then select Uninstall. Windows will remove the program and its associated files. On Mac, open Applications in Finder, drag unused programs to Trash, then empty Trash.

Be cautious with programs that sound like system software — Windows Update, Display Driver, chipset drivers, and security software should stay. If you're unsure whether a program is safe to remove, search its name online before uninstalling. Some programs (like Adobe Creative Suite or Microsoft Office) can be large and worth removing if you don't use them regularly.

Clean up duplicate and old backup files

If you've upgraded your computer or restored from a backup, you may have duplicate copies of files scattered across your drive. Windows sometimes creates System Volume Information and $Recycle.Bin folders that can grow large. Mac creates Time Machine backups that occupy space if you're not using an external drive for them. Check your Documents, Desktop, and Pictures folders for folders named "Old Files", "Backup", or "Archive" — these are often forgotten duplicates.

Before deleting any backup folder, make sure you have a current backup elsewhere. If you're using cloud storage or an external drive for backups, you can safely delete old local copies. If you're not sure whether a folder is a backup, look at the file dates inside it — if everything is more than a year old and you haven't needed those files, it's probably safe to delete.

Empty your Recycle Bin or Trash

When you delete a file, it moves to Recycle Bin (Windows) or Trash (Mac) but still occupies space on your drive. The file doesn't actually disappear until you empty the bin. On Windows, right-click the Recycle Bin icon on your desktop and select Empty Recycle Bin. On Mac, right-click the Trash icon in the dock and select Empty Trash. This is the final step after you've decided what to delete.

If you accidentally delete something important, you have a window of time to recover it before you empty the bin — once the bin is empty, recovery is much harder and may require paid software. So review what's in your Recycle Bin or Trash before emptying it, especially if you deleted a lot of files at once.

Monitor your drive going forward

Once you've cleared space, keep an eye on how full your drive gets. Most people should aim to keep at least 10 to 20 percent of their drive free — if you're regularly hitting 90 percent full, you'll notice your computer slowing down. Set a reminder to check your storage every few months. When you see it creeping back up, repeat the steps above: clear Downloads, move large files to external storage, and uninstall programs you're not using.

If you find yourself constantly running out of space, consider upgrading your drive. A larger internal drive (1TB to 2TB) costs $50 to $150 and is worth it if you work with video, photography, or large datasets. An external drive is cheaper and works fine if you're willing to manage files between your computer and the external storage.

Frequently Asked Questions

Is it safe to delete files in the Windows/System32 folder?

No. System32 contains files your operating system needs to run. Deleting anything there can break your computer. Stick to Downloads, Documents, and the Temporary Files option in Settings — those are designed to be cleared.

What if I delete a file and then empty the Recycle Bin?

The file is marked as deleted but may still be recoverable with data recovery software like Recuva (Windows) or Data Rescue (Mac) if you act quickly. The longer you wait and the more you use your drive, the less likely recovery becomes. If you deleted something important, stop using your computer and look into recovery options when ready.

Can I move my entire Documents or Pictures folder to an external drive?

Yes, but you need to change where your computer looks for those folders afterward. On Windows, right-click the folder in File Explorer, select Properties, go to the Location tab, and point it to your external drive. On Mac, right-click the folder in Finder, select Get Info, and change the location. This way, programs will automatically save new files to the external drive.

How much free space should I keep on my hard drive?

Aim for at least 10 to 20 percent free. If your drive is 500GB, keep at least 50 to 100GB empty. Your computer uses free space for temporary files, updates, and system operations. When you're below 10 percent, you'll notice slowdowns and may have trouble installing updates.

Should I use cloud storage or an external drive for backups?

Both work, but they serve different purposes. External drives are faster for large files and don't require internet. Cloud storage syncs automatically and protects against hardware failure. Many people use both — cloud storage for active files and an external drive for archives.