Artifacts during boot

[Andry]

So today i just bought a new gpu(R7 260x 2gb gddr5 oc) before i install it i removed the old nvidia drivers.After install it instead of showing my motherboard logo artifacts show up and at the bottom of the screen it says Press del to join bios like when the motherboard logo shows up.I have installed the new drivers(not from the cd) i have tried to remove the graphics card clean the connections and stuff but still the artifacts shows up.I installed my brother's gpu (amd saphire 6790) and everything works fine.I installed my r7 260x to my brothers pc and everything is working for him.No artifacts at all.He has a 500w coolermaster solid psu for 6 six years.
PC SPECS : Intel core 2 quad q6600 2.4Ghz (Overclocked 3.0Ghz)
Asus p5kpl/1600,ASUS r7 260x 2gb gddr5 oc,2x500gb western digital blue,Thermaltake litepower 600w black edition,4gb ram kingstone 800mhz.

 

[Joe C]

Thermaltake litepower 600w black edition,

Not the best power supply and if it's more than 5 yrs old, replace it. Corsair, Seasonic, Antec or any other quality brand name PSU