How to Install New Operating System Without Having to Reinstall Applications Installed on Previous Operating System

1. Open the drive in which your windows is installed. Go to program files, click open and you get a list of software installed (applications) on your computer.
   
   
2. Now the software folders which start with "windows" caption are system files and need not be moved as they come pre-installed with the operating system.
3. And the softwares which require a certain registration or key's can't be moved directly as that of those which don't require any type of key for this you require a software named "SymMover" and its free(Google it and download it). with the help of software you can move these applications to non windows hard drives.
4. 
   

   this is how symmover looks like!
   In symmover you add files from your windows hard drive to non-windows hard drives and shift it. 
5. Once you move all your applications. format your system and install your new operating system.
6. After installing your windows operating system install symmover onto your new operating system and restore back your applications files from your non-windows hard drive to windows hard drive folder (in programs folder)using symmover.

source€: www.wikihow.com