FULL PRODUCT VERSION :
java version "1.8.0_73"
Java(TM) SE Runtime Environment (build 1.8.0_73-b02)
Java HotSpot(TM) 64-Bit Server VM (build 25.73-b02, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Windows 2008R2 x64
Microsoft Windows [Version 6.1.7601]

A DESCRIPTION OF THE PROBLEM :
The Offline JRE installer seems to have a strange behaviour on upgrade.

1) If no JRE is installed on my computer, the installation runs fine and the JRE is correctly installed.

2) If a JRE is already installed on my computer (including latest version : 8u73), the installer removes the currently installed version and automatically reboots the computer (whithout prompting for confirmation). After reboot, JRE is not installed.
Previous installers (I can't tell which ones) used to prompt that the version is already installed if trying to reinstall the same version OR just upgraded the JRE if an older version was present on the computer.

REGRESSION. Last worked in version 7u80

ADDITIONAL REGRESSION INFORMATION:
java version "1.7.0_80"
Java(TM) SE Runtime Environment (build 1.7.0_80-b15)
Java HotSpot(TM) 64-Bit Server VM (build 24.80-b11, mixed mode)

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1) Install the jre (with the offline installer) 8u73.
2) After installation, relaunch the installer
3) At the end of the installation, the computer is automatically rebooted and after reboot no JRE is installed any more.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
1) Install the jre (with the offline installer) 8u73.
2) After installation, relaunch the installer
3) A dialog box should prompt that this version is already installed. The dialog box should ask if we would like to reinstall it.
4) If no => Exit
5) If yes => reinstall the same JRE without forcing reboot

REPRODUCIBILITY :
This bug can be reproduced always.