Download it here : http://www.microsoft.com/download/en/details.aspx?displaylang=en&id=28712
Detailed info about its content here : http://support.microsoft.com/kb/2600640
The build number is 5.0.9690.1992.
Note : It was initially released under build 5.0.9689.1985 but was withdrawn due to remaining bug in the package. The currently available version is therefore 5.0.9690.1992.