Train Error

[lijl17]

When I run train_xxx.py in Windows, those Error occur:
ImportError:_ No module named 'models.sync_bn._ext.sync_bn_lib._sync_bn_lib'
This error in line ._sync_bn_lib import lib as _lib, ffi as _ffi
In Windows, python can not use .so document？
I tried to run build.py but failed.
What should I do？

Environment:
Windows10
Python 3.5
torch 0.3.0
torchvision 0.1.9