Here is a link which tells how to remove duplicate OS but I can not understand, Can you put it in layman's term
http://michaelstevenstech.com/xpfaq.html Hi bombaykid,
When you say that, by mistake, you installed XP into a new directory, does that mean that both instances of XP are on the same partition? If so, then give this a try and see if it sorts out the problem..
Go to Michael Stevens' XP FAQ page
Scroll down to #20 "I have two installations of XP on the same partition....." and then click on it to expand the information beneath.
If your XP was corrupted due to malware, then doing a reinstall may make things a lot worse. But it's up to you whether that's the route that you want to take. If so, then run XP Setup, and at the blue "Welcometo Setup" screen you should see options such as:
To set up Windows XP now, press Enter
To repair a Windows XP installation using Recovery Console, press R
To quit Setup without installing Windows XP, press F3
Press Enter
Press F8 to accept the EULA
At this point, setup searches for previous installations of Windows XP, and if it finds any, it will display this screen:
If one of the following Windows XP installation is damaged, Setup can try to repair it.
Use the Up and DOWN ARROW keys to select an installation.
To repair the selected Windows XP installation, press R.
