Magento : How to Set default product quantity to 'one' in Magento i.e. not default zero

1) Go to Admin Panel -> System -> Configuration -> Inventory-> Product Stock Options from the Menu

2) Click on Add Minimum Qty button (next to Minimum Qty Allowed in Shopping Cart option)

3)  Choose Customer Group: ALL GROUPS as you want this to be applied to all users

4) Enter 1 for Minimum Qty

5) Save Config