JustPeachy,
I used these guys for a while when I had an app that needed a Windows+MSSQL Server:
http://www.xxxadulthost.com/
Without a dedicated box, it will be impossible to find someone to let you install DLL''s on the server.
Also, since you are new to adult, you need to be aware that your picture and movie content will at some point be hotlinked. There are some round about ways to prevent this on Windows, but unless there truly is a need for Windows server...you'll make your life much easier by using Linux/FreeBSD.
You will find that adult companies that happen to offer Windows hosting *usually* are not on top of Administrating it properly...lacking updates, etc...