Hmm,......I am wondering if you also have tried (after uninstalling LW and the Java installation) to remove any leftover folder (maybe the one in the hidden data application folder) and delete all entries in the registry, before reinstalling the Java (using the offline installer and restarting) and then the LW (also using the offline installer and restarting).
Maybe an installation in Save Mode (following the above features would do the trick.
From my experience, no machine will ever be the same then another, regardless of how it is assembled and what configuration it has....
Though that's just my 5-cent-worth....
Cheers
FOTH