Now that the final version is out, I tried installing that, only to find the exact same error message as the beta.
Then I downloaded a program called TweakNT to fool Server 2003 into thinking it's actually windows XP.
I converted server 2003 into XP professional, rebooted, the boot screen changed to the XP boot screen, along with other XP only things I noticed, as soon as I tried to log in Windows [censored] the bed and started throwing product activation failures at me (I have a retail copy of server 2003 from my college) and I wasn't allowed to log in because of the product activation [censored].
I rebooted into safe mode and used TweakNT to unconvert my machine back into Server 2003 enterprise and rebooted to find everything normal again.
Thank you Microsoft, for not allowing me to install windows media player 10 on your $650 operating system.