In Windows you can't see file extensions (by default).
You still will be able to see your files extensions if needed by simply following these steps:
1- Click Start button.
2- In search field type folder options and click “Folder Options”
3- Wait for a while, link for “Folder Options” will appear
4- Click the link for Folder Options
5- The Folder Options dialog box will appear
6- UnCheck “Hide extensions for known file types”
7- Click OK button
You will now be able to see the file extensions!!!
1- Click Start button.
2- In search field type folder options and click “Folder Options”
3- Wait for a while, link for “Folder Options” will appear
4- Click the link for Folder Options
5- The Folder Options dialog box will appear
6- UnCheck “Hide extensions for known file types”
7- Click OK button
You will now be able to see the file extensions!!!