no I think you misunderstand P
you could use VM to dual boot .... but it's complicated
I'm saying EITHER dual boot (which is easy enough ... but vista can be odd) OR use VPC2007 to run one OS from another
that'sthe beauty of VPC
you can install it on either Vista or XP
and install virtually (;-) any other operating system as a virtual machine. - vista on vista - vista on XP
you can even create a network of machines (you need a shedload of memory ... but it works).
I use it for testing ... load your OS ... snapshot .... use and break ... restore snapshot .... start again.
even better ... catch a virus and it's trapped in the VM ... so you can afford to be reckless