Please keep in mind that while booking in IRCTC or PRS if you choose Window Seat and you get a Window seat in any coach between D1-D8, most probably it won't be a windows seat. As the coaches are same as passenger trains, so the seating arrangement is 4+1, but in IRCTC database its wrong (3+2). That's why if you choose windows seat and get a seat in between D1-D8 it won't be window seat, even IRCTC chart shows this wrong seating layout. All the coaches before AC CC are general coaches having 4+1 seating layout and and all the coaches after AC CC has normal 2S layout (3+3). So if you want to get confirm window seat then choose between D9 and D10, as D11 is reserved for tatkal tickets.