The third version is already available so you do not have to launch it.
Go to the start screen and type Power Shell.
Using the variable $PSVersionTable, you can view the version by tapping Enter.
In order to launch Power Shell 2, you will first have to create a shortcut on your desktop.
Right click on the desktop and select New from the popup menu, from the drop down menu choose shortcut.
In the Type Name for this shortcut enter PowerShell 2 and click Finish.
Now you've both PowerShell 2 and 3 running in parallel.
If you have difficulties with these instructions then start again from the beginning and take your time to make sure that you do not skip any step. You can also check out some of the many forums and websites that deal specifically with Windows 8. You will find many expert users giving out some excellent tricks, tips and advice. Be sure to check out all of the previous posts to see if your questions have already been answered. You can also ask your own query on any forum to get more personalised assistance. Also, there are many excellent video tutorials that you can use to help with any type of situation or issue that you might be facing in Windows 8. These video tutorials are always a good idea as you can see each step being applied in front of you.
Take a quick trip to your nearest bookstore or library and check out the many books that discuss various issues and tips for using Windows 8. If you are a beginner then it might be a good idea that you learn and do as much research as possible to understand all the technicalities of Windows 8. This will help you with any future issues that you might face with Windows 8.