Hello Dr. Welcome to the Forum.
It sounds like a failed video card. But you should check to eliminate other simple reasons before replacing the card.
A graphics card can also fail due to insufficient power, overheating, driver conflicts, RAM issues, and connection issues.
Power: check to be sure that the PCI-e power connectors are properly plugged into the card. IIRC the 450 uses two 8 pin connectors. Unplug and re-plug these any make sure they are fully seated.
Check your power supply specs and let us know the Brand & Model, how many total watts, and if you can, the number of Amps it puts out on the 12 volt. It should be 22A or more for that card IIRC.
I think we can rule out overheating, as the error occurs right away. The card doesn't have time to overheat.
Driver conflicts might occur when both graphics engines are trying to run at once. Many modern motherboard's BIOS automatically switch off the onboard graphics when a graphics card is detected in the slot. But you should check.
With the 450 installed in the computer, go into safe mode and navigate to the Device Manager and check to see if only one or both graphics adapters are shown.
If both are shown, choose the on-board adapter, right click, and then DISABLE (don't uninstall).
If that makes no difference, and you can go into your BIOS settings, you could disable the onboard graphics manually there (be sure the 450 is still installed when you do this).
In all cases above you want to see if the system will run the 450 w/o problem.
RAM issues can be tested simply by downloading and running http://www.memtest.org/#downiso
for at least 3 passes. There should not be any errors.
Connection issues are tested by re-seating the video card being sure it clicks into its slot correctly and checking the DVI cable connections.
Try those diagnostics and see if they uncover anything. If not you could just have a dud card. If this is a new boxed system then your best back is to bring it back for warranty repair/replacement.