have been trying to help a friend whose Media Center machine refuses to boot with an "error Loading OS" message. I have tried to do a system restore using the HP recovery disks (DVD) it skips merrily on by the CD as the boot device and gives the same message. If I disable the HDD as a potential boot device, it will claim that the disk in the CD/DVD drive is not a bootable disk. I have also tried using an standard XP home setup CD, and a Windows 2K setup CD, but in both cases I get the message declaring that I have not used a bootable disk. The same problem occures ohn both of the CD/DVD drives. Regardless of what CD or DVD I use, if the HDD is not set as disabled and CD set as the 1st boot device, the machine ends up with the black screen and the error loading OS message.