I attempted to install version 20.0.0.204 over ver 19.0.0.190 and get error message saying Administrator permission is needed. But I have Administrator privileges! Examining log file it appears to indicate that it is trying to install in Windows 8. I have Windows 7. I had attempted to install Windows 8 previously, but had to roll back to Windows 7 (64 bit), as my HP printer and Thinkpad docking station did not work in Windows 8. The log file is:
[2015-12-14:22:02:42] Launching subprocess with commandline c:\Program Files (x86)\Common Files\Adobe AIR\Versions\1.0\Resources\Adobe AIR Updater -updatecheck
[2015-12-14:22:02:43] Runtime Installer begin with version 19.0.0.190 on Windows 8 x86
[2015-12-14:22:02:43] Installed runtime (19.0.0.190) located at c:\Program Files (x86)\Common Files\Adobe AIR
[2015-12-14:22:02:47] Performing pingback request
[2015-12-14:22:02:49] Starting runtime background update check
[2015-12-14:22:02:49] Begin Background update download from http://airdownload.adobe.com/air/3/background/windows/x86/patch/19.0.0.190/update
[2015-12-14:22:03:13] Unpackaging complete
[2015-12-14:22:03:34] Runtime updated downloaded
[2015-12-14:22:03:38] User has selected immediate install of the update
[2015-12-14:22:03:38] Starting runtime background update installation
[2015-12-14:22:03:38] Launching subprocess with commandline C:\Users\Anil Cabraal\AppData\Roaming\Adobe\AIR\Updater\Background\updater -update
[2015-12-14:22:04:14] Runtime updater successfully launched
[2015-12-14:22:04:14] Runtime Installer end with exit code 0
[2015-12-14:22:04:32] Runtime Installer begin with version 20.0.0.204 on Windows 8.1 x86
[2015-12-14:22:04:32] Commandline is: -update
[2015-12-14:22:04:32] Installed runtime (19.0.0.190) located at c:\Program Files (x86)\Common Files\Adobe AIR
[2015-12-14:22:04:43] Relaunching with elevation