I need to time some things, thought it would be nice to do this...
Or maybe a better question: Can the date/time format in the Windows task bar be changed?
These are the only customizations you can make using the native Windows tray clock. Milliseconds are not available.
Click the "Additional settings..." button to make other customizations:
00:00:00
upon the press of a button. The task bar will most likely not give you accurate results when trying to time things, that's also the reason why it doesn't have milliseconds...