It's unlikely you're going to find a site where you can download a 10 year old version of the product, tiffany.
You'll likely either have to purchase a used copy from eBay or Amazon or, even better, purchase a newer version of the program. Older versions of the program can be found greatly discounted and, since version 11, the program is light-years head of where it was back in 2006.
In fact, version 4 was pretty much only capable of editing miniDV and tape-based HDV, two formats that are both considered obsolete. If you're editing AVCHD, 4K or video from non-camcorder devices, like iPads and smartphones, an upgrade to version 11 or later will save you countless headaches.