Help on Dell inspiron 15r SE!!!!

hi guys i have bought a new dell laptop last month which came with a pre-installed windows 8 . I was not satisfied with the performance of windows8 . so i installed a clean copy of windows 7 ultimate X64. While installing the drivers for video card ,I frst installed the Intel HD4000 Driver , and took a look at the device manager ,it shows the intel GPU .but it shows Standard Vga Adapter with a small yellow triangle in that place. it says tht "This device cannot start. (Code 10)" when i checked the properties. Plss help me ASAP. thnk u in advance . sorry for a long post