Start with the files taking up the most room

The fastest way to free up space is to find and delete the files that are actually large. Most people assume their computer is full of thousands of small files, but usually a handful of video files, old backups, or duplicate photos are doing most of the damage. Windows and Mac both have built-in tools that show you exactly what is eating your storage.

On Windows 10 or 11, open Settings, go to System, then Storage. Click on "Storage analysis" or the drive you want to check. Windows will show you a breakdown by category — apps, photos, videos, documents — ranked by size. You can click into each category and delete files directly from there. On Mac, click the Apple menu, go to About This Mac, then Storage. You will see a similar breakdown. Both tools let you see which single files are largest, which is where you should focus first.

Before you delete anything, move important files to an external drive or cloud storage. Once you have backed up what matters, you can delete old downloads, duplicate photos, or video files you no longer need. This single step often frees up 10 to 50 gigabytes without touching anything else.

Key Takeaways

  • Use your operating system's built-in storage tool to see which files and folders are largest, then delete the ones you no longer need.
  • Back up important files to an external drive or cloud storage before deleting anything.
  • Uninstall programs you no longer use through Settings on Windows or Applications on Mac, not by dragging them to the trash.
  • Clear your browser cache and temporary files regularly to prevent slowdowns and reclaim space.
  • Run disk cleanup or maintenance tools once a month to remove system junk files that accumulate over time.

Uninstall programs you actually do not use

Programs you installed and forgot about take up space and can slow your computer down, especially if they run in the background. The correct way to remove them is through your system settings, not by dragging them to the trash or Recycle Bin — that leaves behind hidden files and settings that still take up room.

On Windows, open Settings, go to Apps, then Apps & Features. Scroll through the list and look for anything you do not recognize or have not opened in months. Click on it and select Uninstall. Windows will walk you through the removal. On Mac, open Applications in Finder, right-click the program, and select Move to Trash. Then empty the Trash. For programs that came with your Mac or are harder to remove, you can use the built-in Remover tool if the program provides one, or search for the program name plus "uninstall" to find instructions specific to that software.

Pay special attention to programs that run at startup — these slow down your boot time even if you never use them. On Windows, open Task Manager (press Ctrl + Shift + Esc), go to the Startup tab, and disable anything you do not need. On Mac, go to System Settings, General, then Login Items, and remove programs from the list.

Clear your browser cache and temporary files

Your web browser stores copies of every webpage, image, and video you visit so pages load faster next time. Over months or years, this cache can grow to several gigabytes. Clearing it regularly frees up space and can also speed up your browser if it has become sluggish.

In Chrome, Firefox, Safari, or Edge, open Settings or Preferences, find Privacy or History, and look for an option to clear browsing data or cache. You can usually choose a time range — select "All time" to clear everything. Make sure you uncheck "Passwords" and "Autofill" unless you want to lose those too. The cache will rebuild as you browse, so this is safe to do monthly.

Windows also stores temporary files in a hidden folder. Open Settings, go to System, then Storage, and click "Temporary files." Windows will show you what can be deleted — usually old installation files, cache, and temporary downloads. Click the checkbox next to each category and select Delete. This is almost always safe and can free up several gigabytes.

Run disk cleanup or maintenance tools

Both Windows and Mac have built-in tools that find and remove junk files your system creates over time — old error logs, duplicate files, broken shortcuts, and leftover installation files. Running these tools once a month keeps your computer running smoothly.

On Windows 10 or 11, search for "Disk Cleanup" in the Start menu and open it. Select the drive you want to clean (usually C:), then check the boxes next to the file types you want to remove. Windows will show you how much space each category uses. Temporary files, recycle bin, and old Windows installations are usually safe to delete. Click OK and confirm. On Mac, there is no built-in equivalent, but you can use the Storage tab in About This Mac to find and delete old language files or duplicate files, or use a free third-party tool like CleanMyMac X or Disk Diag if you want more detailed cleanup options.

Do not use aggressive "cleaning" programs that promise to speed up your computer dramatically — many of them delete files you actually need or install unwanted software. Stick to your operating system's own tools or well-known programs from reputable companies.

Disable cloud sync if you are running out of space

If you use OneDrive (Windows), iCloud (Mac), Google Drive, or Dropbox, these services sync files to your computer so you can access them offline. If your cloud storage is full, it can slow down your computer and prevent new files from syncing. Check how much space your cloud service is using and either delete files you no longer need or upgrade your storage plan.

On Windows, right-click the OneDrive icon in the system tray and open Settings. Go to the Account tab to see how much space you are using. On Mac, click the iCloud icon in System Preferences and check your storage. If you are running low, you can choose which folders to sync — for example, you might sync Documents but not Photos if photos are taking up most of the space. This keeps your computer lean while still backing up what matters.

Check for malware or viruses if your computer is still slow

If you have freed up space and uninstalled unused programs but your computer is still sluggish, malware or a virus might be running in the background. Malicious software can consume processing power, memory, and disk space without you realizing it.

Windows 10 and 11 come with Windows Defender, a built-in antivirus tool. Open Settings, go to Privacy & Security, then Virus & Threat Protection. Click "Scan options" and select "Full scan" to check your entire computer. This can take an hour or more, but it will find and remove most common threats. On Mac, open System Settings, go to General, then Security & Privacy. Mac does not have a built-in antivirus like Windows, but it does scan for known malware when you open files. If you suspect a problem, you can read a free scanner like Malwarebytes and run a full scan.

If a scan finds threats, follow the prompts to remove them. If your computer is still slow after that, the problem may be hardware-related — a failing hard drive or not enough RAM — and you should take it to a technician for diagnosis.

Frequently Asked Questions

Is it safe to delete files from the Temp folder?

Yes. Windows stores temporary files in C:\Users\[Your Name]\AppData\Local\Temp, and these are almost always safe to delete. They are leftover files from installations, updates, and crashed programs. You can delete them manually or use Disk Cleanup to do it automatically. Close all open programs first to avoid conflicts.

What should I do if I accidentally deleted an important file?

Check your Recycle Bin (Windows) or Trash (Mac) first — files stay there for a while before being permanently deleted. If it is not there, you may be able to recover it with a recovery tool like Recuva (Windows) or EaseUS Data Recovery (Mac), but recovery is not may provide. This is why backing up important files regularly is essential.

Will cleaning up my computer make it faster?

Freeing up disk space and removing unused programs can help, especially if your drive is nearly full. However, if your computer is slow because of malware, a failing hard drive, or insufficient RAM, cleanup alone will not fix it. Run a malware scan and check your Task Manager (Windows) or Activity Monitor (Mac) to see what is using the most resources.

How often should I clean up my computer?

Run Disk Cleanup or clear your browser cache once a month. Uninstall unused programs as soon as you realize you do not need them. Check your storage space every few months to catch problems before your drive fills up completely.

Can I use third-party cleaning software instead of built-in tools?

Built-in tools are safer and usually sufficient. If you use a third-party program, stick to well-known ones from reputable companies like CCleaner or CleanMyMac X, and avoid aggressive settings that delete system files. Many cheap or unknown cleaning programs are actually malware themselves.