IIS Media Pack 1.0 provides media-specific extensions that make delivering media from IIS simple, and cost-effective.  Building on the security, reliability and manageability of IIS 7.0, IIS Media Pack protects media assets as it increases scalability by supporting more concurrent users per server.  IIS supports all media file types, including WMV, FLV, and MP4, and provides a great way to use your existing Web infrastructure to deliver compelling rich media content to clients such as Microsoft Silverlight.
With IIS 7.0 and IIS Media Pack 1.0, you can:

  • Save bandwidth costs by throttling the speed at which content is downloaded
  • Decrease network traffic by metering your media deliveries
  • Monetize media assets with Web playlists that personalize content and prevent ad skipping
  • Intelligently deliver multiple media formats from a single server, including .wmv, .flv, and .mp4 files

Get the 64bit pack @ http://www.microsoft.com/downloads/details.aspx?FamilyID=93d59f79-9555-473d-a07a-e21020d1fc25&DisplayLang=en.

Get the 32bit pack @ http://www.microsoft.com/downloads/details.aspx?FamilyID=2cf81f25-1692-41f7-b916-db5c7e44e6ea&DisplayLang=en.

Source- Technet Blog