Message d'erreur pour carte graphique

Bonjour,

Je viens d'installer une nouvelle carte graphique sur mon PC. Il s'agit d'une NVIDIA GeForce 7950GT 256Mo connectée en PCI EXpress sur ma CM ASUS P5GD1, pentium 4 CPU 3.20GHZ, 1.50Go de RAM.
Le probleme c'est que je reçois un message d'erreur a chaque demarrage et j'ai du mal a en saisir l'importance.

Voila le message:
"the NVIDIA System sentinel is reporting that the NVIDIA - powered graphics card is not receiving sufficient power.
To protect your hardware from potentiel system lockup, the graphics processor has lowered its performance to level that allows continued safe operations.
To remedy the problem, ensure that your NVIDIA graphics card in your system has the supplemental power connector attched. This connection is required and your system may be damage if it is not in place. Please refer to your owner's manuel for complete inspection instructions. Also, the power supply in your computer must be able to supply ample power to power all of the attached periphericals in addition to this extra connection."

Visiblement il y a un certain probleme. Pouvez vous m'aider a comprendre?
Merci