To download the Kiswahili Windows 7 language pack, visit: http://www.microsoft.com/downloads/details.aspx?FamilyID=a1a48de1-e264-48d6-8439-ab7139c9c14d&displaylang=sw
Users simply have to be running a genuine (non-pirated, non-counterfeit) version of Windows 7.
Source: Tech Mtaa