Whenever the computer is restarted customer gets the message “ Performance Warning Your graphics board may not be properly supported by the computer's power supply. The clock speeds have been decreased to reduce power consumption. This may result in slower than expected application performance. Please make sure the appropriate power supply cables are connected to the graphics board “. System Specifications are listed below. This issue is since Day1. I have requested for a day’s time from the customer.
Is the PSU a quality unit? i have had a PSU in the past that was 500W and my graphics card required a minimum of 400W. i had exaclty the same message as you posted. in the end I ditched my £30.00 500W unit and bought an £85.00 unit and have never had a problem since.
If you swap your PSU i'd go for the Corsair units. They are excellent. If you go to Corsair.com you can enter your computer spec and it'll recommend the unit you need. 1Kw is way more than you need. I'd go for either the 750 or 850W unit. The Corsair 1Kw unit is excellent but very very pricey. However if you've got the money go for it.