In this post, you can learn how to delete old Windows files and how to easily and securely clean your outdated files in Windows to release more free space.
Some users find that their computers become quite slow, and the free space on the C drive is suddenly smaller after an update. How does this happen?
▶ Old Windows files
If you check your C drive immediately after a system update, this is probably caused by the old Windows files of the previous version. All relevant files are stored in a folder called “Windows.old”. The Windows.old folder may need almost 20GB which holds all of your prior Windows installations' files and data, such as Windows system files, user account settings, User Profile, User Folder files, and so on.
If you don't like the new version, you can use it to restore Windows to a prior version. You may also search the Windows.old folder for a specific file that was not correctly migrated to your fresh Windows installation.
▶ Is it safe to delete old Windows files?
Normally, your Windows will clean up this folder after 10 days. But if you need available space in a rush, or you’re sure you won’t go back to the previous version, you can manually delete those old Windows files manually. It’s safe.
Since all related files are in one folder, you can easily delete the whole folder to remove all related files. However, some users are not allowed to remove it, and many of them see the report showing the file not found or the target is not a valid file or directory.
This situation might be caused by the following reasons:
◤ The related files are deleted by the system
Different systems have a different time to delete old Windows files.
Windows 7 and older OS, those files will be removed automatically in 30 days after the OS update; Windows 8.1/8, after 28 days; Windows 10, after 10 days.
◤ You don’t have administrator permission
Windows.old folder requires administrator permission from the system to make changes to this folder.
In this part, we’ll show you three ways to delete old Windows files.
But first, we need to switch your account to the administrator. If you have several user accounts on the PC, switch to the administrator account as follows:
Step 1. Open the Windows start menu from the bottom left and select your username
Step 2. Hit "Administrator" on the list.
Step 1. Type “disk cleanup” in the Windows search box, then select Disk Cleanup in the search results.
Step 2. In the pop-out window, select C: to clean up and click “OK”.
Step 3. Wait till the Disk Cleanup for (C :) are open. Then click the "Clean up system files" option.
Step 3. Scroll through the list of folders and select “Previous Windows installation(s)” and click “OK”.
Step 1. Open your Windows Settings and click Settings
Step 2. Click Storage. Windows will take a few moments to analyze your disks and display how you're utilizing your disk space.
Step 3. Click Temporary Files.
Step 4. Check the box next to "Previous version of Windows." If you've recently upgraded, you'll see this option in the list.
Step 5. Click Remove files above the list. A confirmation pop-up will appear.
Step 6. Click Continue to confirm. This removes all selected files, including Windows.old folder that contains your previous version of Windows.
Step 1. 1. In the search box next to the start button, type “cmd” and select "Run as administrator".
Step 2. In the popup window, type the following 3 lines and hit "ENTER" after each of them:
• takeown /F c:\Windows.old\* /R /A /D Y (If the Windows.old folder is not on the C drive, replace C: with the correct drive letter.)
• cacls c:\Windows.old\*.* /T /grant administrators:F
• rmdir /S /Q c:\Windows.old
After deleting the old Windows folder, your C drive may release almost 15GB-20GB of free space.
In fact, there are many old large files like old Windows files on your disk but the sad thing is that it’s impossible to manually find them all and remove them. Thus, if you want to further clean up invalid large files to keep your system and disks in a nice status, then we suggest you use professional cleaning tools. Here, we recommend you AOMEI Partition Assistant for Cleanup, a disk and partition manager for Windows 11/10/8/8.1/7.
This tool has a “Delete Large Files” feature to scan the selected space and filter the large files, and some of them will be marked in red to remind you to cautiously delete (you still can delete them according to your exact needs).
Free Up Disk Space To Keep Your PC Running Smoothly and Efficiently
Step 1. Initiate Delete Large Files. Install and launch AOMEI Partition Assistant for Cleanup. Click the "Delete Large Files" tab.
Step 2. Select a path to scan large files. You can either click "Scan System Drive" to start the scan of your system C: drive. Or, click "Custom Scan" to manually select paths to be scanned. (Here, we take the "Custom Scan" as an example.)
Step 3. After clicking "Custom Scan", all local and external drives on your PC and the common Desktop, Documents, and Downloads paths will be displayed. You can manually select paths to be scanned. Once necessary paths are added, you can click the "Scan Now" button to start the scan process.
Step 4. The scan process might take time. After the scan is complete, all large files found will be listed.
Step 5. You can also check the large files and click the button behind to locate them.
Step 6. Select large files to start deletion. Tick the files you want to delete, and then click the "Clean Now" button to start the deletion.
Step 7. Delete successfully. The deletion might take time. After the process is finished, the selected files will be deleted, and you will get a cleaning completed window displaying how much data you deleted in total.
If you don’t know how to delete old Windows files, then this post will help you a lot. You can try the above 3 ways to delete Windows.old files, and if you need, you can use AOMEI Partition Assistant for Cleanup to deeply clean your disks. In addition, this tool also supports Windows Server 2025/2022/2019/2016/2012(R2) systems.
