Is PHP installed and configured on the server?
If it is create a text file with
phpinfo();
As the only thing in the file. Upload it as test.php then post a link to it in this thread. It could be a misconfiguration.
I always disable power management as well as "green" features in the bios. I also stay away from any component which has "green" features.
They are not made for servers. They throttle down power and affect performance.
Of course if you run a server that has constant activity then the power saving features will never kick in so they won't hurt performance.
Make sure on the server that you have rdp settings set to allow both secure and insecure connections. XP can not connect if it's only set to secure connections.