Dear Mr. Biohead, Thank you for your reply. By "D" I meant that I copied the file onto the D drive in a new folder named vista. Even when I open the folder or the DVD-R I can see what you have asked me to see. I meant, I can see the folders boot, docs, efi, sources, support, upgrade and then icon autorun.inf; bootmgr and bootmgr.efi: internet explorer readme.htm; and setup.exe.. These are the things I can see in the DVD-R. As I have told earlier that when I click on the setup.exe it shows the error message that E:/ setup.exe is not a valid Win32 application . After reading I understand that I need to install by restarting the computer and and press C button. Am I right??? I am not a software person at all but have a great enthusiasm to try new things and thats the reason I am trying this. Any I am a biochemist by profession and so I hope you understand and help me. Many thanks for your reply. Raju