Issue with my new graphics card

Hi i have a problem that stops my card from working, i will get a message stating lost connection openGl stopped, has recoverd.

i bought a new main board and graphics card, my card in asus engt 440
here is my comp specs,
Manufacturer :FOXCONN
Product :A74ML-K
Version :1.0
3gig ram amd phenom 8400 tripple core 2.10ghz
windows 7 ulti 32bit

i get the same problem with OCCT gpu 3d test will last about 2min and my screen will go blank and back to norm over and over untill i am able to stop the test.