There's one window seat which is held back generally - 64A - as it's a bassinet. If you give the exact flight number and date - I or someone else can check the expertflyer view of the seatmap and tell you if it's booked or just blocked.

It opens up at T-72 to book if you call in - but it's likely someone with status would get there first if you aren't willing to pay.

You have to ask what's more important to you. A window? Book one downstairs now and check for the window seat upstairs. Upstairs? Book the aisle and keep checking for an open window seat.