Long gone are the days that standard PCs can efficiently mine Bitcoin. You need specialised hardware (ASICs), and even then you'll be hard pushed to make money unless you can get very cheap electricity.
there is no point mining with my PC now though I have an AMD graphic card. it is too slow and too little.
You can get the best graphics card available and you'd still be too slow. As said, you need specialised hardware (ASICs) these days to even have a chance.
I'm quietly smiling at your naivete. What did you do? Download some mining software, thinking you could get rich quick by mining bitcoin yourself? Those days are long gone.
