GUIMiner does not appear to be detecting my GPU. Under available devices, I am only able to see my CPU. I have an AMD Radeon 7670M GPU, that I have the most updated driver for and can confirm that it is enabled and working.
In my Device Manager, the GPU shows up under Display Adapters and there are no errors.
Screenshot of my GUIMiner GUI, as well as the summary of my GPU from GPU-Z:
Why is this GPU not being recognized? For the record, I have been able to use GUIMiner previously using the same graphics card, but have not used it for months and since that time I have upgraded to Windows 8.1 (x64).