I would like to solve the "invalid media location" Error message while installing the Portal server 5.1 & 6.0 in RSA.

I have downloaded portal server and stored in my C:\DownloadDirector\RSAPortal5101. I have downloaded C82XSML, C82Y1ML and C82Y2ML. At the time of installation, it asking to select the CD-2.

Any one is having solution, please let me know where I am doing wrong.