As noted earlier this week, the final versions of the Windows Installer 4.5 redistributable and Windows Installer 4.5 SDK have been released.  I installed the Windows Installer 4.5 SDK this weekend and noticed a few interesting things about it that I wanted to point out because this release of the SDK is a bit different from recent versions of the Windows Installer SDK that have shipped.

• The total download size for the Windows Installer 4.5 SDK is 6.8 megabytes.  This is the first time I recall a small standalone Windows Installer SDK being released like this.  In the past, getting the Windows Installer SDK required installing a core subset of the Windows SDK or Platform SDK.  This meant you had to download and install a rather large SDK to get copies of Windows Installer tools like Orca.
• The Windows Installer 4.5 SDK includes a copy of the Windows Installer help documentation in CHM format.  It is located at %ProgramFiles%\Windows Installer 4.5 SDK\Doc\msi45.chm if you install the SDK to the default location.  This CHM file has not shipped with the Windows Installer SDK in a while, and it is a handy reference for Windows Installer-specific information, especially on systems that do not have Internet access.

In addition to the above, the Windows Installer 4.5 SDK includes the following components (which have also been shipped in previous versions of the Windows Installer SDK)

• Updated versions of a set of useful tools, including the installer for Orca (Orca.msi) and several others.  The tools are located at %ProgramFiles%\Windows Installer 4.5 SDK\Tools if you install the SDK to the default location.
• Headers, libraries, patch building samples and sample code that can be useful to Windows Installer developers.