How and where can I store large downloadable files with NOP commerce?

Hi
Can anybody help with this? I have tried to upload video files as saleable downloads to a site running NOP but the server times out after a maximum of around 10 megabytes. I presume this is the maximum file size available on the database and have read that it is not the best place to store files like this anyway as it would slow down the downloads considerably and put a large load on the server.
I would like to store the files on the files-system on the server and ensure that they are secure and efficiently downloadable. Any help would be greatly appreciated.

1. Go to product variant details page (admin area)
2. Ensure that 'Use download URL' is checked
3. Specify 'Download URL'
That's all

What would the download url be for this...
In my wwwroot folder I have several stores that I wish to sell digital downloads. Most of the digital product will be the same for all the stores. So rather then storing the same files over and over again inside each store. I have created a download director in the root folder that all the stores can use.

wwwroot/
store1
store2
store3
store4
downloads

How can use the direct link to the download folder when it is outside of the store folder?
When I try to use the direct server link i get errors because the field on the product detail page assumes the download directory is located inside the stores root directory.

How can this be changed?

I found a solution to my question above by creating a virtual folder in IIS for each site that points to the real folder in the wwwroot directory. Tested and I was able to download the item without an error.