Broadcom SDK and BTW 6 are two different things.
If you had purchased a broadcom-based bluetooth dongle, then you will need to install BTW 6 (that came with it) to utilize the features of the dongle, eg A2DP streaming.
In this forum, we have dedicated Software Development Kit (SDK) for development of applications to be used on WICED solutions, eg 20736/7. The SDK is a complete IDE environment and you do not need to install Visual C++.
I download setup.exe from here: Development Kit Downloads | Broadcom
but there is only Documentation, Samples and header files, lib-files and brwapi.dll hmm... if me need develop software than me need a some IDE like Visual studio.