Parts needed.

Hello, thank you for posting,

We should be able to assist, but to further review, we will need to see the window sash open. We will need to see clear images of the operator arm and the lock attachment that engages to lock the window. From there we can get a better idea of the overall style for possible replacements. If the window lock is broken to where it cannot be unlocked, please review the video on the page for assistance. Thank you!