If your file name does not end in a period and some letters, Windows does not know what program to use to open it. Be aware that by default Windows hides file extensions, so the extension might be there and you're just not seeing it. It is easy to change this so that you can see the extension. For instructions, search the internet on "show file extensions" and select a link to one for your version of Windows.
If you know the program that should open it and you know that you have that program installed, you can:
- Right-click on the file name and select the program you want from the list that you'll see; or
- Rename your file, adding ".xxxx" to the end, where ".xxxx" is the extension for the right program.
If you don't know what program should open the file, you may have to ask the person who sent it to you.
If you don't have a program installed that works with the extension on the file you are opening, you won't be able to open the file.
The solution is to either:
- Install a program that will open the file. This is practical when there are free programs to open them, such as Adobe Reader to open .pdf files.
- Ask the person who sent you the file to send it to you in a different format, which can be read by a program you DO have installed. This is usually practical for something like a Word document that was created by a later version of Word than you have installed -- the sender can use the "save as" function of Word to create a "doc" version instead of the default "docx".
Sometimes, "things happen" that cause Windows to associate a particular file extension with a program that isn't the one you want. If you know what program you do want, it is easy to fix this.
To get instructions:
- Type "Change the program that opens a type of file" in Windows help on your computer; or
- Search the internet for "change default programs in Windows".
