Windows DLL loading error for PyTorch due to missing Visual C++ Redistributable – suggest improved user guidance or system dependency management

[Virtuoso461]

Summary

When using uv to manage a Python project that depends on PyTorch on Windows, the import of torch fails with an OSError: [WinError 1114] indicating that c10.dll (or one of its dependencies) failed to initialize. This is caused by the lack of the required Visual C++ Redistributable on the system. Unlike Conda, which automatically installs such system-level dependencies, uv does not handle them, leading to a confusing error for users who expect a seamless environment setup.

Platform

Operating System: Windows 11 Pro 23H2 (build 22631.1), x86_64 Architecture: 64-bit

Version

uv 0.10.9 (f675560 2026-03-06)

Python version

Python 3.11.9

[zanieb]

It is currently out of scope for us to handle managing system dependencies.

I think we could add a hint to the error, but I don't think we currently show hints based on the output of uv run commands.

[zanieb]

Can you provide the full error message please?

[miturian]

Not OP, but I am getting the same error.
After starting python within a virtual environment (named 'DISCO') managed by uv:

>>> import torch
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\virtual_environments\DISCO\Lib\site-packages\torch\__init__.py", line 285, in <module>
    _load_dll_libraries()
  File "C:\virtual_environments\DISCO\Lib\site-packages\torch\__init__.py", line 268, in _load_dll_libraries
    raise err
OSError: [WinError 1114] A dynamic link library (DLL) initialization routine failed. Error loading "C:\virtual_environments\DISCO\Lib\site-packages\torch\lib\c10.dll" or one of its dependencies.