MSI Error 2869 is a common issue with MSI installations on Windows Vista.

"The installer has encountered an unexpected error installing this package. This may indicate a problem with this package. The error code is 2869"

This error can occur when the UAC (User Access Control) feature of Windows Vista is enabled. If you are defined as administrator on Vista, you are only temporary granted administrator privileges when running programs. Therefore, MSI Custom Actions that interact with the system and require administrative privileges, such as the Content Matrix Console - Website Edition installer, will fail to run because MSI Custom Actions will impersonate by default.

There are two potential workarounds:

From a Command Line prompt, run the following command (as an administrator): msiexec /i MySetup.msi

Temporarily disable the UAC. The install the application. After Content Matrix Console - Website Edition has been installed, re-enable the UAC.

This information below is for Windows 2012:

In Windows server 2008 R2 and Windows Server 2012 unless you actually turn off UAC in the registry is it not actually off (Even when you drag the bar down to Never Notify in the Control Panel) and will cause all kinds of Install and just odd issues. Doing this has fixed all kinds of things for me lately.  To turn it off follow below.

HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionPoliciesSystem

Over on the right-hand side, you should see a setting for EnableLUA, which you’ll want to customize as follows:

• UAC Enabled: 1

• UAC Disabled: 0