Running Out of Disk Space? How to Find What's Filling Your Drive
"Your disk is almost full." It's a warning almost every computer user sees eventually. And it matters: a nearly full drive slows your computer, can stop updates from installing, and leaves no room for new files.
How much free space do you need?
A good rule of thumb is to keep at least 10–15% of your drive free, or around 20 GB minimum on smaller drives. Major system updates can need even more temporarily.
Step 1: See what's using the space
Don't delete things blindly. Find the big items first.
• Windows: Settings → System → Storage. You'll see a breakdown by category (apps, temporary files, documents, pictures and more). Click Show more categories for detail.
• Mac: System Settings → General → Storage. Click the ⓘ next to each category to review files.
• For more detail: Free tools like WinDirStat or WizTree (Windows) and GrandPerspective or DaisyDisk (Mac) show a visual map of exactly which folders are biggest.
• Mac: System Settings → General → Storage. Click the ⓘ next to each category to review files.
• For more detail: Free tools like WinDirStat or WizTree (Windows) and GrandPerspective or DaisyDisk (Mac) show a visual map of exactly which folders are biggest.
Step 2: Quick, safe wins
Empty the Recycle Bin or Trash
Deleted files still take up space until you empty it.
Clean up temporary files
• Windows: Settings → System → Storage → Temporary files. Review the list and remove what you don't need. Be careful with the Downloads option, which deletes everything in your Downloads folder.
• Windows: Settings → System → Storage → Cleanup recommendations suggests large files and unused apps.
• Mac: In Storage settings, review the Recommendations section.
• Windows: Settings → System → Storage → Cleanup recommendations suggests large files and unused apps.
• Mac: In Storage settings, review the Recommendations section.
Turn on automatic cleanup
• Windows: Turn on Storage Sense to automatically clear temporary files and old Recycle Bin contents.
• Mac: Turn on Empty Trash Automatically in Storage settings.
• Mac: Turn on Empty Trash Automatically in Storage settings.
Step 3: Find the big stuff
The usual suspects:
• Downloads folder: installers, old videos and files you've forgotten about.
• Videos: phone videos, screen recordings and downloaded movies are huge.
• Old phone backups: iPhone backups on a computer can take many gigabytes.
• Games: modern games can take 100 GB or more each.
• Duplicate photos: especially if you've imported the same phone photos multiple times.
• Videos: phone videos, screen recordings and downloaded movies are huge.
• Old phone backups: iPhone backups on a computer can take many gigabytes.
• Games: modern games can take 100 GB or more each.
• Duplicate photos: especially if you've imported the same phone photos multiple times.
Step 4: Uninstall apps you don't use
• Windows: Settings → Apps → Installed apps → sort by Size.
• Mac: Drag unused apps from the Applications folder to the Trash, or use Storage settings → Applications.
• Mac: Drag unused apps from the Applications folder to the Trash, or use Storage settings → Applications.
Step 5: Use cloud storage smartly
OneDrive, iCloud Drive and Google Drive can keep files online only until you need them:
• OneDrive: Right-click a folder → Free up space.
• iCloud: Turn on Optimize Mac Storage in iCloud Drive settings.
• iCloud: Turn on Optimize Mac Storage in iCloud Drive settings.
Your files still appear in folders but only download when opened.
Step 6: Move files to an external drive
Large archives like old photos, finished projects and video are good candidates for an external drive. Just remember: if a file exists in only one place, it isn't backed up.
What NOT to delete
• Files in C:\Windows, Program Files or macOS System folders.
• Anything labeled as a driver, recovery partition or system file.
• hiberfil.sys and pagefile.sys files directly (Windows manages these).
• Anything labeled as a driver, recovery partition or system file.
• hiberfil.sys and pagefile.sys files directly (Windows manages these).
When in doubt, leave it alone.
Step 7: Consider a bigger drive
If you're constantly fighting for space, upgrading to a larger SSD (where your computer allows) or adding a large external drive may be the long-term fix.
The bottom line
Look before you delete. Use the built-in storage tools to find the big items, clean up temporary files, uninstall what you don't use, and let cloud storage handle files you rarely open.
