Installed software

[Tom Barnes-Lawrence]

OK, as this question doesn't seem to be getting noticed in my previous,
slightly long-winded thread, I'll ask it alone in it's own thread:

How do installer programs in Windows record that they've installed what
they've installed?

And how then do I convince *other* installers running through Wine that
I already have some program X installed?

This is still in relation to expansion packs for Total Annihilation not
installing because they think I haven't got the main game installed
already (even though I have, and it works fine apart from the sound).

(whilst waiting to get internet access back in order to post this, looks
like someone else just asked a similar question, sorry if it has the
same answer)

Thanks in advance,

 Tom Barnes-Lawrence