I bought this machine last Augest. It is a dos version (MSI CR400-X) which means it doesn't come with any OEM OS. And I have just flashed the latest ver. BIOS for the official site. I am currently using winXp and would like to upgrade to win7 ultimate. Now, I have on my hand a copy of win7 dvd and wondering if I could just install it or not. If not, what would be needed in order to activate it?