Run .msi installer as admin

There is no right click option, Run as administrator for .msi files.  You can, however, run the CMD prompt as Admin, then the following:

  msiexec  /a "Installer File Name.msi"

Another useful command to crack open an .msi installer file:

  msiexec /a "Installer File Name.msi" /qb TARGETDIR=c:\temp