PerroneFord, Are you sure you didn't just download and install the ReadMe file?
I did the download directly through Lightroom 4.2, under the Help menu, Check for Updates option. You get both the 32-bit executable file (387MB), and the 64-bit executable (394MB), plus a 1MB ReadMe and a little installer file. I just checked the Adobe site and they list the download as 771.5 Megabytes. Adobe download estimates are 35 1/2 hours for a 56K modem, 4 3/4 hours for a DSL hookup, and 1 1/4 hours for a T-1.
I don't know what you installed, but it wasn't the Lightroom 4.3 update!