How to install JRE 1.2.2 in JAVA 6

[Casper2011]

Hi,

I would like to use an old java program (*.jar), only it won't work because it says that it will only work with 1.2.2.

Now I have tried to install JRE 1.2.2_017, but now the newer programs will not work.
I also saw that in my configuration panel that the 1.2 engine was not properly installed and somehow the setup file of the 1.2.2 is not closing properly.

How can I make this older program work or how can I install the older 1.2.2 engine without disturbing the newer engines?

Thanks in advance.

[oliver_watkins]

install 1.2. Use Eclipse to define which project uses which version of Java