On Windows, Java prevents starting the Installer twice by creating (two) lock files. If those files exist, Java Installer show the Message: “Another Java installation is in progress (…)”.
If Java Installer crashes, or Windows crashes during Java Installation, the installer cannot delete the lock files when finalizing.
Solution:
Deleting the lock files, unlocks the Installer and Java can be installed again.
The lock files are located at:
C:\ProgramData\Oracle\Java\JAVA_INSTALL_FLAG
%USERPROFILE%\AppData\LocalLow\Sun\Java\JAVA_INSTALL_FLAG
%USERPROFILE%\AppData\LocalLow\Oracle\Java\JAVA_INSTALL_FLAG