Symptom: clicking on .msi file ran the installer, that removed old 5.x version and appeared to load new version, but on successful finish there was no folder for 7.2.0 under C:\Program Files and LibreOffice was not functioning (e.g. double clicking on a .odt file did nothing).
I discovered that simply double clicking on the .msi file in my Downloads folder from an account with admin rights was not enough.
The solution was to open a command prompt with Admin access and run the install from the command line:
i.e. Click Start, type cmd then select Run as Administrator
Then cd to where the msi file was and run it from there by typing the name of the file and hitting
After that, everything was working perfectly!