Several iterations of Mac OS have allowed dual boot capability with Windows. Essentially you can partition your hard drive using the boot camp program and allocate space to other operating systems.
Installation of Vista on using bootcamp:
Follow the prompts through creating your partitions.
You'll want to allocate at least 40+ GB of space for Vista. More space is required obviously if you want to add significant programs to it.
**To install Vista put the Vista disk inside BEFORE you click "Start Install" otherwise bootcamp will crash.**
Allow the Vista install to start.
Pick the partition you want to install Vista on.
Vista will complain about the partition not being the correct type... click on Advanced or Options on the Vista install screen and then click "Format". Vista will then do what it should have done in the beginning and prepare the partition and will install it's files.
Starting the Operating System You Want:
Restart your Mac and hold down the Option key as the screen goes dark during reboot. This will trigger the bootcamp menu and it will list the installed operating system that are available to boot to.
You can change your default by booting to your Mac side and changing the default in your system options bootcamp section.
Inevitable Driver Problems:
One of the lingering problems however has been the issue of drivers for Vista. The internet is filled with all kinds of bad advice on this topic and you are likely to get in trouble if you dig around too long. Before you waste any time on that try the easy way:
1) boot to your Vista side
2) put your Mac OSx CD, or bootcamp CD in if bootcamp comes on a separate disk (generally it will be the OS install disk itself)
3) it magically installs all the drivers you need
If you follow this advice you will save yourself (as I can attest) hours of technical support and hours and hours of surfing the web and trying poorly informed advice from message boards after Apple technical support says that this is a "Microsoft problem" and you should talk to them instead.
I do know from experience that Microsoft USED to support these drivers and removed them from the Vista install (I wonder why?) So it is BOTH an Apple and Microsoft problem. Let's hope Apple tech support reads this blog and finds out how to install Vista properly using Boot Camp.