New installations of Windows hide all file extensions, except for Windows components, that would appear in Explorer or an application dialog box that displays file names. File extensions are ...

Microsoft hides file extensions in Windows by default even though it's a security risk that is commonly abused by phishing emails and malware distributors to trick people into opening malicious files.

One of our readers reported that all the file extensions have changed to some unknown file format. If so, it could be a virus! If a virus has changed all the files extensions to unknown applications, ...