My problem is that my graphics card is not available in the compute device option:

Instead it shows my Intel Core 2 Duo, which is my processor. Already set CYCLES_OPENCL_TEST=ALL and CYCLES_OPENCL_SPLIT_KERNEL_TEST=1
My Specs
Processor: Intel Core 2 Duo E8300 @2.83GHz
Graphics Card: AMD Radeon HD 6670
Graphics Card Driver: AMD Radeon Software Crimson Edition
OS: Windows 7 64bit