WinUSB is a generic USB driver provided by Microsoft, for their operating systems starting with Windows Vista but which is also available for Windows XP. It is aimed at simple devices that are accessed by only one application at a time (for example instruments like weather stations, devices that only need a diagnostic connection or for firmware upgrades). It enables the application to directly access the device through a simple software library. The library provides access to the pipes of the device. WinUSB exposes a client API that enables developers to work with USB devices from user-mode. Starting with Windows 7, USB MTP devices use WinUSB instead of the kernel mode filter driver.