Microsoft sells four different Vista DVDs in non-emerging markets: Retail/OEM 32-bit, Retail/OEM 64-bit, VL (Volume Licensing) 32-bit and VL 64-bit.
The Retail/OEM DVD contains all editions of Windows Vista except Enterprise. The license-key purchased determines which version will get installed; the VL DVD can only install Business or Enterprise edition. Users can "unlock" the features of the Home Premium and Ultimate editions at any time by purchasing a one-time upgrade license through a
Control Panel tool called
Windows Anytime Upgrade. Similarly one can upgrade the Business edition to Vista Ultimate. End-users purchase such licenses from Microsoft's partners and OEMs, not directly from Microsoft.