Note: The info on this page is based mainly on running the 32bit offline installer in Win7 and WinXP.
Be careful especially with version 8.20.
It is based on a completely different installer, many things have changed (see below).
Also I received one report that the installer of this version triggers a reboot
when using SCCM, where previous versions did not do this.
None of the 8.x versions remove version 7.67.
Version 8.20 does not even remove 8.11.
8.11 does remove 8.5, and 8.5 does remove 8.0
When the installer is ready, it fires up the default web browser showing this page:
http://java.com/en/download/installed.jsp
This page asks for permission to scan for and remove previous versions.
The release notes of 8.20 say that the MSI can only be downloaded by customers who pay for a support contract.
"A new Microsoft Windows Installer (MSI) Enterprise JRE Installer which enables user to install the JRE across the enterprise, is available. See Downloading the Installer section in JRE Installation for Microsoft Windows for more information. The MSI Enterprise JRE Installer is only available as part of Java SE Advanced or Java SE Suite. For information about these commercial products, see Java SE Advanced and Java SE Suite."
Oracle must be the only company to charge users for a runtime library.
The web page http://www.java.com/en/download/help/msi_install.xml, which described how to get the MSI file from the offline installer, now only returns an error message ("Access Denied").
Extracting the MSI file from the offline installer does however still work the same way as before. The extracted file is even better, because it is now self-contained, no separate CAB file any more.
Maybe this note only refers to a separate downloadable msi file, which might have existed somewhere on password-protected support pages, and is now a bit more restricted.
Version 8.20 installs to C:\Program Files\Java\jre1.8.0_20.
All previous 8.x install to C:\Program Files\Java\jre8.
Version 7.67 installs to C:\Program Files\Java\jre7.
Might be a non-intended side effect of the new installer.
Probably explains why 8.20 does not overwrite 8.11.
8.20 occupies only 77 MB versus 130 MB of version 8.11.
Did they leave something away, or is it more efficient?
Version 8.20 works, although the installer warns that it is not supported.
Versions 8.0, 8.5, and 8.11 cannot be installed
(cannot find RegDeleteKeyExA in ADVAPI32.dll).