With the passage of time, unused files accumulate and take up hard drive space on your computer. Periodically cleaning these unnecessary files improves your PC’s performance and frees up storage space. However, determining which files are safe to delete can be confusing for many users. Deleting the wrong files can cause system instability or data loss.
In this comprehensive guide, we provide tips on identifying and safely removing redundant files from your Windows PC. We cover various file types like temporary files, previous Windows installations, downloaded program files, browser cache/history, Recycle Bin contents and more. Read on to optimize your PC while avoiding any critical data loss.
Types of Files That Are Typically Safe to Delete
Here are some common file categories that can usually be deleted safely:
Temporary Files
Temporary files (or temp files) are created during program executions and PC use. They are meant for short-term storage and can be safely deleted. Temporary file locations in Windows include:
- C:\Users\[username]\AppData\Local\Temp
- C:\Windows\Temp
- C:\Users\[username]\AppData\Local\Microsoft\Windows\Temporary Internet Files
Downloaded Program Files
When you install a program on your PC, the downloaded installation files are often left behind and can be deleted. These are typically found in:
- C:\Users\[username]\Downloads
- C:\Users\[username]\AppData\Local\Temp
Windows Update Files
Windows update files are downloaded when you install system updates or upgrades. Old updates that have already been installed are safe to remove by deleting the SoftwareDistribution folder at C:\Windows\SoftwareDistribution.
Browser Cache and History
Web browser cache contains temporary internet files, while history stores information on sites visited. Both cache and history can become large over time and can be cleared to free up drive space.
Recycle Bin Contents
Files deleted through Windows are moved to the Recycle Bin. Emptying the Recycle Bin removes these files permanently and frees up used space.
How to Identify Large Files
Sometimes large files that are not in use can take up significant drive space. Here are some ways to identify them:
- Use Windows Explorer to view files by size and look for large folders/files.
- Use the Disk Cleanup utility to find system files that can be removed.
- Use third party utilities like WinDirStat or TreeSize to visualize disk usage and detect large files.
Make sure to verify that any large files found are indeed not required before deleting them.
Files You Should Avoid Deleting
While removing unused files is usually safe, some file deletions can cause problems. Avoid removing the following:
Windows System Files
Files in C:\Windows\System32 and other Windows folders are critical for the OS. Don’t delete files with system extensions like .dll, .exe, .sys unless you are certain.
Program Files
Generally avoid deleting files in C:\Program Files or other program installation folders, as these are required for installed software to run.
Drivers
Don’t remove driver files (*.inf, *.sys) for hardware devices you need, as this can cause them to malfunction.
Personal Files
Don’t delete your personal data files stored under Users\[username] like Documents, Music, Pictures etc. These contain your valuable data.
Tips for Safe File Deletion
Here are some tips to delete files safely on Windows:
- Empty Recycle Bin – Use this instead of permanent file deletion initially.
- Use Shift + Delete – Deletes files permanently without sending them to the Recycle Bin.
- Check associations – Before deleting, see if any programs have dependencies on the files.
- Delete folders – Delete entire unnecessary folders instead of individual files.
- Confirm deletion – Enable Recycle Bin confirmations before permanent file deletions.
Use Disk Cleanup
Disk Cleanup allows you to safely delete temporary files, previous Windows installation files, Recycle Bin contents and more. Use this built-in utility for convenient disk space cleanup.
Delete One Location at a Time
Don’t randomly delete files from different locations simultaneously. Remove files from one folder at a time and check system stability before further deletions.
Back Up Important Data
Before starting any mass deletion, backup critical personal files and data to an external drive as a safety net.
What type of files can be deleted from Program Files?
It is generally not recommended to delete files within the Program Files folder, since this contains installed program code and dependencies. However, some files that may be safe to remove include:
- Redundant subfolders left over after unclean program uninstalls. Check if any data files remain before deleting.
- Update installer files from already updated programs.
- Text files with program settings that can be reset within the application.
Avoid deleting actual program executable (.exe) files, dynamic link libraries (.dll), component files (.ocx) etc. Only delete files that you can confirm are not actively used by programs.
Is it safe to delete files in the Windows, Prefetch folder?
The Prefetch folder (C:\Windows\Prefetch) contains temporary data meant to speed up application launch times. These files can become outdated and usually be deleted safely. However, some precautions include:
- Don’t delete the whole Prefetch folder – just old files within it.
- If using an SSD drive, disabling prefetch provides no benefit so don’t delete files.
- Regularly used application files may better be left untouched.
- Some prefetch files may be open when Prefetch is enabled – close them before deleting.
It’s preferable to use the inbuilt Disk Cleanup utility to remove Prefetch files past the retention period. Overall, deleting specific Prefetch files causes no major issues in most cases.
How can I safely delete Temporary Internet Files?
Here are some recommended ways to safely delete browser Temporary Internet Files (cache):
- Use your browser’s clearing options – Chrome, Firefox and others have settings to clear cache and other temporary data. This is the easiest and most reliable method.
- Delete folder manually – You can browse to the cache subfolder in the browser’s profile folder and delete files. However, clear cache in browser settings first.
- Use CCleaner – This freeware utility has options to safely clear internet cache and temporary files from all major browsers.
- Don’t delete subfolders under cache – Cache folders like IndexedDB, Service Worker etc. should not be manually deleted.
Avoid deleting the main browser profile folder itself – this contains saved passwords, history, bookmarks etc. Only remove the temporary internet files subfolder within it.
Is it safe to delete msmpeng.exe from the Prefetch folder?
The file msmpeng.exe located in the Prefetch folder is related to Windows Defender and provides antivirus protection. In most cases, it is safe to delete this file from the Prefetch folder if you are looking to clear space:
- Msmpeng.exe will be recreated in Prefetch the next time Windows Defender runs a scan, so functionality is not impaired.
- The actual msmpeng.exe file is stored in the Windows\System32 folder and will remain untouched.
- Prefetch is only used for startup optimization and not necessary for Defender to run.
However, refrain from deleting msmpeng.exe from Prefetch if:
- You notice issues with Windows Defender after deleting it.
- You have a third-party antivirus and have fully disabled Windows Defender.
- You are using an SSD drive, in which case there is no real benefit to clearing Prefetch.
In summary, deleting the Prefetch version of msmpeng.exe is fine in most cases to clear space, but monitor Windows Defender afterwards for any potential issues.
What is Discord’s cache folder and is it safe to delete?
Discord cache contains temporary files that can be deleted to save disk space. Here are some key points about Discord’s cache:
- It is stored locally in %appdata%\discord\Cache on Windows.
- Includes items like temporary voice chat files, update files etc.
- Cached messages, channel history etc. are not deleted when clearing cache.
- Full cache clears may temporarily affect performance until rebuilt.
- Individual cached files can also be deleted safely.
- Cache is fully recreated on next Discord launch if deleted.
Overall, Discord’s cache can be safely cleared fully or partially without losing any critical data or settings. The app’s functionality remains intact. However, you may encounter temporary lags while the cache rebuilds.
Can Windows update backup files be deleted safely?
Windows update backup files can usually be safely removed to free up space. Here are some tips on deleting these backups:
- Navigate to C:\Windows\SoftwareDistribution\Download and delete files ending with .bak, .old, tmp, .wbk, etc.
- Only delete backup files for updates that have already been successfully installed.
- Don’t delete files ending with .exe, .msu or .cab – they are pending installers.
- Use the Disk Cleanup tool to automatically remove outdated backups.
- Sometimes update backups may be open – close them before deleting.
- Disable ‘Allow backup of system files…’ option to prevent backup creation.
As long as an update has been successfully installed earlier, its backup is no longer useful and can be safely removed. This provides an easy way to gain back gigabytes of storage space in some cases.
How can I find and delete previous Windows installations?
When upgrading your Windows version, the previous installation files may remain on your PC taking up space. Here is how to delete them safely:
- Type ‘Free up disk space’ in start menu search and select the settings to view old Windows installations.
- Delete any previous Windows versions you are sure you don’t need to rollback to.
- Alternatively, use the Disk Cleanup tool and check ‘Previous Windows installation(s)’ to remove them.
- Navigate to C:\Windows.old and delete this folder if your PC lacks sufficient space.
- Delete any Windows.old or $Windows.~BT folders present on other partitions/drives as well.
Removing previous Windows installations can recover several GBs of disk space in many cases. Ensure proper backups exist before deletion to avoid issues.
What files are safe to remove during Windows 10 disk cleanup?
Windows 10 Disk Cleanup allows you to safely delete many unneeded files. Here are some of the safer options to enable when freeing up space:
- Temporary Files – Removes temporary folders like %temp% used by programs and Windows.
- Downloaded Program Files – Deletes .msi, .exe installer files after software is installed.
- Windows Update Cleanup – Deletes previous Windows updates that are outdated.
- Previous Windows Installation(s) – Removes files from previous Windows versions.
- Recycle Bin – Empties your Recycle Bin completely.
- Windows Error Reporting Files – Removes log files created from error reporting.
The above options are generally safe to use for most users. Avoid deleting your personal files and currently active system files. Review size benefits before and after cleanup.
Conclusion
Cleaning your PC by removing unused and redundant files can significantly improve its performance and storage capacity. However, caution should be exercised to avoid deleting any vital system or data files. We recommend using Windows’ inbuilt Disk Cleanup utility as it allows you to safely delete many unnecessary files.
When manually deleting files, stick to common file types like temporary files, uninstallers, browser caches etc. Avoid system, program, driver or personal data files unless completely sure they are obsolete. Following the tips and best practices covered in this article will help you to effectively free up disk space without causing any problems.