I have installed NT Workstation 4.0 on a Dimension XPS T550 for more stablility. The machine is now running perfectly expect it will not power off when 'Shutdown' is selected. I have made the change in the registry to allow for the 'Shutdown and Power Off' option in the shutdown menu, but the machine always reboots instead of powering off.

I have searched the Dell sites for a patch to allow this but cannot find one and I also e-mailed Dell (Europe) but they are un-willing to help me as the machine was shipped with Win98.