Windows 7 is released but it is not strongly to be tried by everyone confidently as some of them may not want to give up their current installation of XP or Vista.

Here is a way that you can install Window 7 in dual with XP and Vista, so that you still can maintain your current version of Windows, besides trying the new Windows 7.

Step 0: Download the Windows 7 Beta and Burn It to a DVD

Step 1: Partition Your Hard Drive
– Partition Your Hard Drive in XP
– Partition Your Hard Drive in Vista

Step 2: Install Windows 7

LifeHacker has writter post on how to dual boot Windows 7 with XP or Vista.
You can read the full article here