how to solve duplicate location while installing ADT(plugin) in eclipse IDE

PROBLEM:    during the installation of ADT in the eclipse IDE,The small window appears with message "duplicate location".each time this message appears and installation is not allowed and can't be completed:

solution:
   in the website,we can find several solution to this problem.we may get  annoyed due to several answer and our problem may not be solved,i also got same problem while installing plugin.i searched this problem in the net but i could not found the best solution.

with a lot of work in it ,i fix this problem.here is the solution to this problem.it could solve your problem in an easier way:

1:  firstly if you have got the ellipse IDE ,that is compatiable without installation. in this case delete the eclipse folder
2. unzip the zip folder which we have downloaded earlier.
3. after this install the ADT ,doing this it wont ask for duplicate location again.