To check your existing SSH public key in Windows for use with Bitbucket, you can follow these steps:

Open the command prompt or PowerShell.

Navigate to the directory where SSH keys are stored, typically C:\Users[YourUsername].ssh.

Use the command type id_rsa.pub to display your public key.

This process assumes you've already generated an SSH key. If you haven't, you'll need to create one using the ssh-keygen command before proceeding.