Colour management questions: monitor & printer

Greetings,
I'm trying to understand how the Windows Vista colour manegement system
works.

I own a Eye One display sensor and performed some measurements to build some
monitor ICC profiles. My laptop, besides it's own display, is connected
sometimes to an external monitor so I've created 2 ICC profiles.

* the first question is if there's a way to let Vista automatically use the
proper profile according to the display in use.

** the second question is: once the proper monitor profile is applied, do I
need to profile my printer(HP Photosmart C5200 series)? If so how can I
profile\calibrate it?

*** third question: when printing images, do I need to use a profile-aware
software? That is, old image viewers (printing capable) can still be used or
they would simply ignore colour profiles?

**** last question: my camera embeds into the pictures a sRGB IEC61966-2.1
color profile; should I apply the same profile to the monitor and the
printer, or Vista (or the image viewer, or the printing program) will
convert correctly the profile, enabling true "what you is is what you get"
on prints?

Thanks