Downloaded Arduino IDE. Attempted to "Run as Administrator" the Arduino.exe file and got an error that Java Environment is missing or corrupted. Same thing after downloading the latest JAVA version.
Windows 10 64 bit
Firefox Browser
Plenty of memory.
Which IDE download did you use? There are three options for Windows on the Downloads page:
"Windows Installer, for Windows XP and up"
"Windows ZIP file for non admin install"
"Windows app Requires Win 8.1 or 10" (the "Get" button)
I would recommend uninstalling your current IDE installation, downloading a fresh copy, and installing it again.
You don't need to install Java because the Arduino IDE comes bundled with its own JRE, so it runs independently from whatever Java you might have installed separately.