on windows Vista where Java is not installed, WPP say that is "Not Installed" where should be "Not Applicable"
That's wrong. Your 'IsInstallable' rule clearly states that ALL COMPUTERS
Java7 U51 should install it
on windows 7 where is already installed the u51, WPP say that is "Not Installed" where should be "Installed"
This mean that the MSI Product code you have used in the 'IsInstalled' rule have not been detected.
On a client computer, open regedit and select :
then search for the string 'Java' and look at the value : UninstallString
you can search into this RegKey too :