Update: This post is no longer useful since Microsoft has stopped providing support fo this hack.

As the size of hard drives increase with more and more installed applications, it is better to install heavy applications (Such as Photoshop, .NET, and many other) on the drive on which Windows is not installed.

By default, Windows XP and Windows Vista both use “C:\Program Files” as the default base directory location where new programs are installed. However, you can easily change the default location or installation drive by using a simple registry hack.

Make sure to backup your registry before trying to edit the registry.

Do :-