nvidia-smi: command not found

Either NVIDIA drivers aren't installed, or nvidia-smi exists but isn't on PATH. On Windows, nvidia-smi.exe lives in C:\Windows\System32\ after driver install. On Linux, it's in /usr/bin/ or /usr/local/cuda/bin/.

On Linux:

# Find it
which nvidia-smi
locate nvidia-smi
# If found but not on PATH:
export PATH=/usr/local/cuda/bin:$PATH
# If not installed:
sudo apt install nvidia-driver-535  # Ubuntu — pick latest

Then reboot.

On Windows:

# Add to PATH if installed but missing
$env:Path += ";C:\Windows\System32"
# Or run with full path
& "C:\Windows\System32\nvidia-smi.exe"

On WSL2: Don't install NVIDIA drivers inside WSL. Install the Windows driver only — WSL2 inherits it. nvidia-smi should work in your WSL terminal automatically.

If nvidia-smi fails after install: /dev/nvidia0 may not exist. Try sudo nvidia-smi once to initialize, then it works for users.