Notes about the JBK file extension:
Incorrect file associations could be the result of underlying issues within your PC system. As such it is highly recommended to scan your PC for invalid registry entries, unused processes and other unfavourable system settings to identify slowdown issues.
The JBK file type is primarily associated with 'Jot + Notes' by King Stairs Software. A note/outliner application for Windows. Newer versions save the backup with a dual extension: .JOT.BAK.