Red Eye Rose received a file with a strange extension. She doesn't know into what program she should load it. Neither does Windows.

Sometimes, when you try to open a Word file it fails to open and displays the following message – Word cannot open the file because the file format does not match the file extension.

When you double-click on a file in Windows 8, Windows will automatically open that file using a program that has been associated with that file's extension. There may come a time, though, that ...

Files with the .avery file extension are created by Avery's Design and Print Online Web application. You can't double-click these files to open them; you must open them from Avery's Web page.

Windows 11 can make it easier to access your extensions through apps. Here's how. Windows 11 can keep track of the apps you open and set them by default for faster navigation.