How to create rich tooltips and rich balloons in notification area

I've been wondering, whenever you call the ShowBalloonTip method of the NotifyIcon class, you get a balloon tooltip like this:

Fig1: Standard Balloon Tooltip

Some applications and Microsoft products are able to display more than those 'simple' balloon tips.
Here are some samples:

Fig2: Windows Update Balloon Tooltip

_{(source: microsoft.com)}

Fig3: Hardware Driver Installation Balloon Tooltip

Fig4: Hardware Removal Tooltip (Program: USB Safely Remove)

A good look at Figures 2, 3, and 4 reveals they aren't standard balloon tooltips!

Fig2 has a different shape, possibly from setting the Region property. It also has a custom icon which is much bigger than the standard ToolTipIcon.

Fig3 uses the standard shape (I think) but it has a custom icon which needless to say is larger than the default ToolTipIcon size.

Fig4 uses a standard ToolTipIcon but it has a different shape.

My question is how does one create any of the 'rich' balloon tooltips that are seen in the notification area in .NET? I can handle WinAPI as well as it can produce the necessary output.

You have to use the Win32 Function Shell_NotifyIcon. You can set the dwInfoFlags member of the NOTIFYICONDATA structure to NIIF_USER in order to use a custom icon for the balloon tooltip.

On Windows XP Service Pack 2 and later you can use the hIcon member to specify a custom icon.

On Windows Vista and later the NOTIFYICONDATA structure contains the addiional member hBalloonIcon. You can use this member to specify a custom icon if you have set the cbSize member to the correct size of the extended NOTIFYICONDATA structure.