Official support for this software has largely ended since Qualcomm acquired CSR. While the exact "Yahoo" source mentioned in your query is likely a dead link or a result from an old forum, you can find the WHQL-certified installer through third-party archives: Electronic Specifier Verified Archives Internet Archive hosts the full CSR 4.0 Harmony Universal Bluetooth Stack. Driver Repositories : Sites like TousLesDrivers
The CSR Harmony Wireless Software Stack 2.1.63.0 is a software development kit (SDK) designed for creating wireless applications using CSR (Cambridge Silicon Radio) Bluetooth modules. This software stack provides a comprehensive set of tools, APIs, and documentation to facilitate the development of Bluetooth-enabled products. Csr Harmony Wireless Software Stack 2.1.63.0 Download Yahoo