Max Quanity

[lat9]

I am trying to change the default "Product Qty Maximum" from 0 to 1

I am also trying to put a default "1000" in the "Products Quantity" box

Can someone tell me how to do this.

This can be done, procedurally, without changing any code. Create a product that you will use as a template for future products that you define, setting "Product Qty Maximum" to 1 and "Products Quantity" to 1000. To create a new product, use the product Copy icon (the blueish-purple one with a C in it) to create a copy of that template product. Edit that copy, providing the details of the new product -- its maximum will be set to 1 and quantity to 1000, just like the "template" product.