It looks like you got a BrokenPipeError: [Errno 32] Broken pipe.
Could you reduce the number of workers in your DataLoader to zero and see if your code still breaks?
Also, are you using the if-clause protection? Since you are using Windows, multiprocessing should be guarded with:
import torch

def main()
    for i, data in enumerate(dataloader):
        # do something here

if __name__ == '__main__':
    main()

Have a look at the Windows FAQ 10 for more info.