When browsing through a Windows computer’s root directory, users may occasionally stumble upon a mysterious folder labeled $Windows.~BT. It’s hidden by default and typically exists in the main partition, often raising concerns about whether it’s important or if it can be deleted to free up space. Understanding what this folder does can help users make better decisions about system maintenance and storage management.
TLDR:
The $Windows.~BT folder is created by Windows during an upgrade or installation process. It stores backup files, logs, and previous Windows versions, allowing users to revert to an earlier version if needed. While deleting it might free up disk space, doing so will prevent rolling back to a previous version of Windows. Generally, it’s safe to delete the folder if you’re not planning to downgrade your system, but it should be done through system tools to avoid problems.
What Is the $Windows.~BT Folder?
The $Windows.~BT folder is a temporary folder created by Microsoft Windows, most often during:
- Upgrading from one version of Windows to another (e.g., Windows 10 to Windows 11)
- Installing major updates or service packs
- Participating in the Windows Insider Program
It functions as a storage repository for backup files, system logs, setup files, and previous Windows configurations. Essentially, it acts as a safety net, enabling users to revert to an older version of Windows if the current version encounters problems or doesn’t perform as expected.
Why Is It Hidden?
Windows hides certain folders like $Windows.~BT by default, mostly because they contain system-critical files. Tampering with or deleting contents without proper understanding can lead to system instability. By making it hidden, Microsoft ensures that casual users don’t delete it without realizing its purpose.
What Does It Contain?
The contents of the $Windows.~BT folder can vary depending on what type of Windows installation or upgrade was performed. Typical contents include:
- Previous Windows installations: These files enable rollback to an older version of Windows.
- Log files: Used for diagnosing errors during the upgrade or installation process.
- Setup files: Temporary files required for completing the installation or update.
- Windows Update cache: Files related to pending or recently applied updates.
The size of the folder can vary, but it often ranges from a few hundred megabytes to several gigabytes, especially if it contains a previous version of Windows. For users with limited disk space, this can become a concern.
Is the $Windows.~BT Folder Safe to Delete?
Technically, yes — you can delete the $Windows.~BT folder, but it’s essential to understand the consequences before doing so. Deleting it can save valuable disk space, but doing so will also eliminate your ability to roll back to a previous version of Windows. This is particularly important if:
- You’ve recently upgraded Windows and may want to revert back.
- Your system is experiencing post-upgrade stability issues.
- You are part of the Windows Insider Program and frequently try preview builds.
If you decide that you won’t need to revert back to a previous version and your Windows setup is stable, it’s safe to remove the folder using recommended methods.
How to Delete the $Windows.~BT Folder the Right Way
One should avoid manually deleting the folder, as it can cause permission errors or incomplete deletions. Instead, use the built-in Disk Cleanup tool:
- Type Disk Cleanup in the Start menu search bar and launch the tool.
- Select your system drive (typically C:).
- Click on Clean up system files.
- After scanning, check the box labeled Previous Windows installations.
- Click OK to begin cleanup.
Disk Cleanup ensures all dependencies are removed safely and any necessary permissions are handled internally.
Alternative Method Using Storage Sense
For those using Windows 10 or 11, the Storage Sense feature can automate this process:
- Open Settings > System > Storage.
- Scroll to Storage Sense and turn it on.
- Click Configure Storage Sense or run it now.
- Set a schedule and choose to delete temporary files, including previous installations.
When Not to Delete the Folder
There are specific scenarios where keeping the $Windows.~BT folder is advisable:
- You’ve upgraded Windows within the last 10 days and may want to rollback.
- You’re troubleshooting issues that require access to upgrade logs.
- You’re actively testing builds as a Windows Insider.
Deleting the folder in these situations can limit your recovery options or ability to diagnose system issues.
How to View the Folder
To find and examine the folder:
- Open File Explorer.
- Navigate to the root directory of your system drive (usually C:\).
- Click View in the toolbar, then select Hidden items.
- You will now see the $Windows.~BT folder listed.
Even viewing the folder isn’t necessary unless you have a specific reason, like checking upgrade logs or verifying disk usage.
FAQs
-
Q: What creates the $Windows.~BT folder?
A: Windows creates it during upgrades, major updates, or when installing preview builds via the Insider Program. -
Q: Is it safe to delete $Windows.~BT?
A: Yes, but you will lose the ability to revert to a previous Windows version. Use Disk Cleanup or Storage Sense to delete it safely. -
Q: How large can the folder be?
A: It can range from a few hundred MB to over 10 GB, depending on the upgrade and installation history. -
Q: Will deleting it affect anything important?
A: It will remove rollback capability and may erase some diagnostic data. It won’t affect your current Windows installation if removed properly. -
Q: Can the folder come back after deletion?
A: Yes, it can reappear during future upgrades or updates, as Windows recreates it as needed.
In conclusion, while the $Windows.~BT folder does serve a purpose, it’s not essential for long-term system operation once you’re confident no rollback is needed. Just make sure to follow recommended deletion methods to ensure system stability and security.
