Hey!
Probably I have not been clear.
Imagine clean Windows 7 installed on new computer, added to network
domain and installed DC Agent.
Then, Java installed, Java is stuck on "Ready to execute"
even if I leave computer turned on overnight.
So, problem is not that Java is already running, as it was not
installed earlier.
I just tried new installation on new PC and even with reboot it is
stuck, but remotely I can navigate to \\pc\C$\Program Files\Java\jre7,
after next reboot I will get fatal error but Java will be installed.
Can you try to install Java 6u45 with default settings and check if
everything is ok?