You can try retrieving the data from the Backup Folder of Notezilla . To know how to do this, visit the following page:
Note that for locking newly created(other than the ones having the forgotten master password) Notezilla sticky notes, you can only change the master password.
To change the master password,click on "Forgot Password" link from Advanced tab of Notezilla Preferences. To access Notezilla 's Preferences, right click on Notezilla icon and choose Preferences from the menu.
If you use the new master password on an existing locked note, you will still not be able to get the content of the note(unlock) since the password for that particular note is different.
Unfortunately, it is not possible to open a locked Notezilla sticky note without it's master password.