I've recently purchased a brand new (no-OS) PC. I installed my legitimate copy of Windows XP Home Edition (w/SP2) on it and it loaded everything without a hitch. Once I started the upgrade process to Windows Vista Ultimate with my legitimate Vista Ultimate Upgrade dvd, everything was going along smoothly until after the second reboot. It came up to the "Upgrading Windows....." screen with the check marks next to "Copying Windows files", "Gathering files", "Expanding files", and "Installing features and upates". In bold black letters it now reads "Completing Upgrade.." and it appears to be completely locked up. Mouse won't move and I see no hard disk activity. I tried this once earlier, and I know that if I reboot my machine, it'll come up and tell me the installation failed and it'll roll my OS back to XP. Has anyone else encountered this, and if so, what do I do?