• Run the Windows operating system that you want to use
  • Go to Windows Button then search Run and then type %windir%, and then click OK.

Or




  • Yo can go with My Computer then click your windows installation Folder (Default C: drive).
  • Remember This folder will open.(This folder is Working windows folder).Don't try to delete or remove or rename.
  • Find the Windows old folder and remove or delete it and click yes to confirm.


  • Now Right click on My Computer or Computer then click Properties.
  • Now select Advance tab with Startup and Recovery then click setting then it will show The Startup and Recovery dialog box

  • Under System startup, click Edit to modify the Boot.ini file.


The Boot.ini file opens in Notepad and looks similar to the following:




  • Click on file in notpade and click save as then backup copy of the boot.ini that name as boot.old.Then exit to close it.


In the [boot loader] section of the Boot.ini file, identify and then delete the line of text for the Windows operating system that you want to remove. For example, if the Windows folder that you removed in step 4 was for the Microsoft Windows XP Home Edition operating system, remove the following line of text from the Boot.ini file:



  • click the file in notpade and save it as boot.ini file.then exit it.


  • Click OK to close the Startup and Recovery dialog box.
  • Restart your computer.

Source : Microsoft 

How to remove second installation file or Multiple Operating System