Currently I have MOSS 2007 running on it and I wanted to install PerformancePoint Server 2007 on it. Specifically the Planning Server setup.
Problem is that it complains that you are not running Windows2003 SP1 in a non domain environment.
To get around this use the following command line
msiexec /i PPLSrv.msi SKIPREQCHECK=1
This will remove the check for the installer and allow you to install on Vista.
To install the updates just change the command line to
msiexec /update PPLSrv.msp SKIPREQCHECK=1
You can use this for the other MSP files as well if required
Update: 21-11-2009
Following on from the comments here is a screen comparison if you use the command line above
And without
You will notice that the next button is enabled to allow you to do the install.