If it doesn't - what's the easiest way to replace one lighting set with another?
Thanks
Perp

In P7 and P8 you have a choice.   Clicking on the single-check button replaces,
clicking on the double-check button adds the lights without removing the old.
(The labels on the single and double check are confusing in P7; you just
have to remember which is which.)

In previous versions the only choice was to replace.

You also have the option to delete all lights through the Scripts drop-down window.

Ockham - excuse my ignorance - by single check and double check buttons am I right in assuming they are not in the usual bar on the right of the screen? (I have Poser 7)
Thanks
Perp

In 7 those buttons are at the bottom.  They are the same as the single and
double check buttons for figures.  

I think the buttons don't appear until you actually select (single-click)
one of the light sets in the list.

 Actually.. IIRC, the lights aren't properly deleted in Poser 7 - they aren't in Poser 8 at least - but they're turned off. I've taken to use the Python Script Delete All Lights before adding a new lightset into my scene. That works.

There is a discrepant behavior how light sets install into the Poser scene.  Older sets for earlier Poser versions appear to add more lights while current sets delete and substitute new. It is dependent upon how the installation script is written to respond.  I agree with TrekkieGrrrl, I have seen lights switched on and off without deletion.  However, in TerraDome, for example, present lightsets are deleted and new ones are installed.  Again, in agreement, the most practical solution is to use the Python Script Delete All Lights before installing new.  I would also recommend deleting lightset before saving a document intended to be imported into a different scene.  Definitely there you will notice an additive effect.

Thanks All,
Hborre - Is that Python script already incuded in Poser 7, or will I need to go get it?

perp

That Python script should be built in.  IIRC, it should reside under utilities.  It definitely exists in PoserPro and P8, and PP is the variant of P7.

OK, found it, thanks hbore