I recently had to replace my personal laptop and ended up with a Vista Home Premium machine (not by preference!).
Running OOo from my USB key on this machine, I had to select the JRE as usual**, but something was odd: the "use a java runtime environment" checkbox was not checked (it usually is) and no JREs popped up in the list, not even after several minutes (the list can take a while to populate while the computer is being searched for Java installations).
No problem, I thought, I'll just choose the one in Common Files like I usually do. But I couldn't select the JRE because when I navigated to the JRE location and clicked OK, the "Select Path" dialog just popped up again, empty as if I had just clicked the Add button. It would do that over and over and over again. The only way to get out of the dialog was to cancel or close it, but then I was still left with no JRE.
The solution was odd... I had to navigate to the locally installed JRE first, in the Add button's Select Path dialog. I didn't even have to actually select the JRE, it populated the list as soon as I navigated there (C:/Program files/Java). For some reason, once the list was populated, I could then add the JRE from Common Files.
**I realize there's a way to fix it so I don't have to keep setting the path to Common Files, but I haven't gotten around to doing that yet, and I can live with setting the path when I need Java until I do get around to fixing it.