@anantguptadbl From the link, it seems that the PyTorch installation command includes the CUDA runtime, which  I think is sufficient to use use GPUs for training and testing. Thus, we do not need to install manually CUDA for Windows.
Could you (or anyone) please correct me if I am wrong?

  
    
    
    Is it required to set-up CUDA on PC before installing CUDA enabled pytorch? 
  
  
    No CUDA toolkit will be installed using the current binaries, but the CUDA runtime, which explains why you could execute GPU workloads, but not build anything from source.