I installed `tensorflow` using `pip install tensorflow` within Anaconda virtual environment on Windows.

I tried to test whether GPU is enabled, and type

```
import tensorflow as tf
print("Num GPUs Available: ", len(tf.config.experimental.list_physical_devices('GPU')))

```

and got

```
Num GPUs Available:  0

```

My system does have CUDA and CUDNN enabled, as I do not have a problem installing PyTorch GPU version. How do I enable GPU for TensorFlow?