What is default program in windows 7:
The default program for a file type is the program that Windows 7 uses to open that file type. Like Windows 7 uses notepad to open .txt files.

In this post, I will show you how to set default files types for a application in windows 7. Windows 7 will use that application to open all files types that you have selected.

Step 1:
Open control panel and select view by: Small icon

Step 2:
Click “Default Programs”.

Step 3:
Click “Set your default programs”.

Step 4:
From the left column, select the program that you want to change it’s default file associations for. Now click “Choose default for this program”. Check the extensions that you want to associate as default files for this program. Click “Save” button.