If you don’t see file name extensions when you view files in File Explorer: To learn more about how to change which program will open a file, read Change default programs in Windows 10.

You can change a file name extension, but that won't convert the file to another format or change anything else about it except the file name. Most file name extensions are compatible with more than one program that you have installed. For example, the docx extension tells your computer that Microsoft Word can open the file and to display a Word icon when you view it in File Explorer. In expenses.xlsx, for example, the first part of the file name is expenses and the extension is xlsx.Įxtensions tell your computer which application created or can open the file and which icon to use for the file. (It's just below the first set of radio buttons.) Click OK.Windows file names have two parts separated by a period: first, the file name, and second, a three- or four-character extension that defines the file type. Remove the check mark from the box labeled Hide extensions for known file types.In the menu, click Tools » Folder Options.Double-click My Computer or any folder icon.(It's a couple of lines below the first set of radio buttons.) Click OK. In the Folder Options dialog, select the View tab.If you don't see Organize, press Alt+T, release the Alt key, and press letter O. Click the down arrow next to Organize, and select Folder and search options.Double-click Computer or any folder icon.Check (tick) the File name extensions box.Double-click This PC or any folder icon.How do I make file extensions visible so that I can change them? If extensions are hidden, you can't do that, so you need a way to display file extensions. The standard way to do this is for the sender to change the extension to TXT, and the receiver to change it back to ZIP or REG or XLSM or whatever. But you may need to send us a file of a type that your mailer rejects, or we may need to send you one. You can right-click the file and select Properties » Details to see its full name, or look at the Type column in Explorer to find a description of the file type, such as Microsoft Excel Worksheet. Most Windows installations are pre-configured to hide the file extensions, so a file actually called MyModel.xlsx would appear in Explorer as MyModel. The file extension tells Windows what program to run when you double-click the file - for an XLSX file, that's Microsoft Excel. For example, a file called MyModel.xlsx has a file extension of XLSX. Nearly all files in Windows have a 'file extension', usually three or four letters after a dot.

How to see file extensions windows 10