Windows XP 32 Bit: What is best version of Java and Microemulator?

[Daj A]

Great program.  Microemulator 2.0.4 works great on my W7 computer.  Question though:

But my mom has a Windows 32 bit XP machine.  I installed Microemulator 2.0.4 on her computer.  When we try to run it though the computer says "What program do you want me to run this file with."  I don't think Java is installed on her computer.  I can't find it anywhere.

What version of Java do you think would work best?

Thanks.