Mark is right; in order to be able to reinstall or upgrade java, without the current install MSI file, remove the corresponding entry from the registry !
just search by yourself, or use a reg file like this:
Windows Registry Editor Version 5.00
; 1.7.5
[-HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Installer\Products\4EA42A62D9304AC4784BF238120750FF]
; 1.7.25
[-HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Installer\Products\4EA42A62D9304AC4784BF238120752FF]
play this file and reboot, java is able to install at new !
it would be good to have a reg file containing all of the possibilities for every java version ^^
if it's not sufficient, M$ provides a tool for corrupted installs :
http://support.microsoft.com/mats/Program_Install_and_Uninstall
2
Also see Java Old JRE Installation Issue.
– Karan – 2012-11-12T02:24:02.243