Most of the times you have been in a situation where you have two windows installed on two different drives. One of them is Windows 7 and other version you want to delete but you don’t know how to delete windows folder on other drive because the OS doesn’t let you do so.
There are many ways to do so. One of them is to Take Ownership. You can do so by Right Clicking on Folder->Properties->Security->Advanced->Owner->Edit, Select your username, and check the “Replace the owner on sub containers and objects” box and click OK, and then try deleting it.
If the above option doesn’t work for because Windows 7 doesn’t allow you to delete the system folder in this way, this was the case with me.
So the solution is to try to download and install a very useful utility by clicking here. Installation procedure is described on the link.
It will show you a context menu item as show below.
Clicking the Take Ownership item will take the ownership of folder and its contents. Then you can just right click and delete that particular folder.
Hopefully you will be able to get rid of other version of windows which you don’t want to use or you cannot delete..