Cannot run 1.8.5 Installer

I have Windows Vista x64 and I could not get the trial installer to run for version 1.8.5. I found an earlier version (1.2.1) and the installer worked.

How can I get the version that I have installed updated? I turned off all of the anti-virus software and even tried safe-mode.

The version 1.2.1 works well and I was able to register my license, I would just like to update it.

I figured out a work around. I installed the Beta version 1.7.1, then used the Updater from there. Now I have 1.8.5 successfully installed!