Was able to fix my issue with the Unable to start ComfyUI v0.8.23. I’m running Windows in a laptop RTX 5070ti and used these commands in PowerShell to manually install pyTorch CUDA 12.8. Just correct your “User” path in the command before running it. Hope this helps you all.
# Activate the ComfyUI venv
C:\Users\User\Documents\ComfyUI\.venv\Scripts\activate
# Uninstall CPU torch
C:\Users\User\Documents\ComfyUI\.venv\Scripts\python.exe -m pip uninstall torch torchvision torchaudio -y
# Install CUDA 12.8 torch
C:\Users\User\Documents\ComfyUI\.venv\Scripts\python.exe -m pip install torch torchvision torchaudio --index-url https://download.pytorch.org/whl/cu128
# Confirm Cuda is running
C:\Users\User\Documents\ComfyUI\.venv\Scripts\python.exe -c “import torch; print(torch.cuda.is_available()); print(torch.cuda.get_device_name(0))”
And you should get an output of: True
NVIDIA GeForce RTX 5070 Ti Laptop GPU