Vista start-up & networking w/ XP

I have two questions if someone can assist or at least direct me where to
find some answers. Where is the "correct place" to store start-up scripts in
Vista and Windows 7? Traditionally in Windows XP this is done using local
policy editor and setting the startup/shutdown scripts. Because I have Vista
Home Premium, this feature is disabled. I know this is probably stored some
where in the registry, but I am not sure where this is.

The second question has to do with networking. I have two machines one
running Vista Home Premium and the second is a Windows XP machine. I have
setup shared network drives on both machines (they are networked using
workgroups ). The share are never a problem when seen from the XP host, but
on the Vista machines sometimes they seem to disappear and the connections
are not reestablished at startup. I have seen suggestions that I create a
startup script to disconnect and reconnect the shares at startup. That is
fine but, I would love to find out why they disappear in the first place.
Any thoughts suggestions.

Thank you.