Model: 6511-SU, also works for 5308
Operating System: Windows 98 (Note: might work with other versions of this os.)
It installs the software for Hewlett-Packard 6511-SU USB Internet Keyboards. These keyboards have 15 hotkeys (inc Standby), media controls (stop/play/etc.), and a volume KNOB instead of buttons. The keyboard also has a built-in USB 2.0 2-port hub (ports located at each end of keyboard). The keyboard was designed for Windows 98 but it works fine on Windows XP Pro if using this software. Supposedly this software also works for model 5308, but I can't back that up.
This utility (NOT A DRIVER, keyboard functions without it) allows you to configure the hotkeys and on-screen display (for when you push a button).
The settings can be accessed by going to Keyboard in Control Panel and selecting the Buttons tab.
NOTE: If you (like me and many others) use the TAB key to navigate windows faster, this is for you: DO NOT USE THE TAB KEY WHEN IN THE KEYBOARD CONTROL PANEL. Your system may lock up.