Microsoft blocks core Windows 11 feature to prevent hacks

Microsoft has disabled one of the most useful features of Windows. Latest update for Windows 11 disables Explorer preview for all files downloaded from the Internet. The tech giant noted that this setting is made to prevent your computer from being infected by malware disguised as a normal document.

In an update to its support page, Microsoft confirmed that it will disable the preview feature in Explorer. update October 14. This measure will be applied by default to all files marked with the Internet Mark (MotW), an identifier used by the operating system to identify files downloaded from the Internet or received from places considered untrustworthy.

“This change addresses a vulnerability that could cause NTLM hash leaks if users are able to preview files that contain HTML tags (such as a <> link, etc.) that reference external routes,” says Microsoft. “Attackers can use this preview feature to intercept sensitive credentials.“.

If the Preview pane is active in File Explorer, Windows 11 will display the message: “The file you are trying to view may damage your computer. If you trust the file and the source you got it from, open it to view its contents.“.

It is worth noting that this policy will only apply to files tagged MotWas other documents or workflows will not be affected.

Why will Windows 11 File Explorer Preview be disabled?

When you download a file from the Internet, Windows adds a special tag to it via an alternate data stream on NTFS systems. Brand MTV has an immediate effect; For example, if it’s an Office document, it might open in Protected Mode or display a warning when you try to run it. This identifier has been used since Windows 7, and today it is assigned by browsers such as Chrome, Edge, Firefox, as well as others based on Chromium.

Although Is it possible to bypass internet security blocking?It is not recommended to do this if you are careless when browsing the Internet. If you are sure of the origin of the downloaded file, you can remove the tag by right-clicking and selecting Characteristics and clicking on the option Unblock. This can also be done for a file share, although in this case you will need to use the Security tab of the Internet Options control panel to add the address to the list of trusted sites.

Lock Preview will apply starting with the Windows 11 Update on October 14, 2025. and some versions of Windows Server. Windows 10 users don’t need to worry about this.