Windows 7 Professional installation on a laptop with 2 disks

Hi everybody!
It is my first post here so forgive any mistakes I make.
I have a laptop Acer Aspire 4315 with 2 disks. One XP and one Windows 7
I had a problems with the key activating my windows 7 and for that reason I downloaded again Windows 7 Professional.
I can do it for free as a student in a greek university.
I want to install Windows 7 on laptop and have only them.
I download them from the msdnaa website and when the download was completed there is the message that I attach.
What shall I do?

Thanks a lot!
I know there shall be many people to solve my problem!!!

This website is not affiliated, owned, or endorsed by Microsoft Corporation. It is a member of the Microsoft Partner Program.