♥ fina♥ says:

You can install Vista on a separate partition and choose which to run when you start (or restart) the computer. A couple of things to consider:
1) Vista will barely run on 1GB or RAM. If you have less, forget it – it’ll crawl. And unless you have at least 2GB, you won’t be happy with it.
2) Computer operating systems don’t talk to hardware, they talk to driver programs. Drivers talk to the hardware (and are written by the hardware manufacturer). If you can’t get a Vista driver for a particular piece of hardware in your computer, you can’t use that hardware in Vista. Make sure you can download the drivers for ALL the hardware (for which there are drivers – things like ATA hard drives don’t need them) on that computer from the computer manufacturer’s web site in the Vista version. If you can’t you probably don’t want to waste your money buying an OS you won’t be able to use.

Colanth says:

First of all your computer will need to meet the vista requirements for hardware, so that it can run smoothly. Most new and recent computers meet the requirements so that shouldn’t be too hard. You can check that on http://www.microsoft.com/windows/windows-vista/…
Second off, if you want to run xp and vista on one computer you will need to partion off the hard drive into two parts and install one operating system on each part, this is called dual boot up. This is a bit trickier and may require someone with a few of skills with computers if you don’t yourself.
Good luck and enjoy vista, its much better than xp and easier to use.

Crimson says:

You can install Vista inside your XP like any other program by using a free software by Microsoft called Microsoft Virtual PC 2007.http://www.microsoft.com/downloads/detai…
Use the below tutorial to install it.(the guide is for installing xp in vista but you can follow the same procedure to install vista inside xp)http://www.intowindows.com/install-run-x…