As a test unplug your hard drives SATA connector and try booting from the DVD again. If my hunch is correct you will get a No operating system found, please insert system disk, or similar message. I think the flashing cursor is because your system is skipping by the DVD and still trying to boot off of the hard drive. When you used this DVD on your other systems did you do a clean install or did you run the install from the previous version of windows? It might be a good idea to put that DVD in one of your other PC's and verify it is in fact bootable. If some one knows of a good utility to do that would they please post it, I have to admit thats one thing I'm not up to speed on.