WIA Driver Versioning
A driver reports the version of WIA (or STI for legacy drivers) that it supports in the version field that is returned from IStiUSD::GetCapabilities. Drivers typically set this field to STI_VERSION, which is defined in Sti.h.
In the Windows Driver Kit (WDK) for Windows Vista, the value of STI_VERSION is greater than the value of STI_VERSION in previous operating systems. If a driver has the Windows Vista value for its driver version, it must support Windows Vista IStream data transfers.
A Windows Vista driver that adheres to the new Windows Vista WIA model must return STI_VERSION_3 in the version field that is returned from IStiUSD::GetCapabilities.