If you boot to the DVD, you should not get a bootmgr message. It should give the Windows loading files black page followed with the Pick a Language window.
If you are not getting that, make sure the DVD is listed first in the boot options, or select it using a Boot to key such as F 12 or whatever.
If the DVD is good and the Drive is good, then possibly there is some problem with the internal connections. But basically, the system is not being directed to the correct location for the boot sequence. If you have other external drives, remove them just in case they are booting instead of the DVD.