Windows 10 64 位， pip 死活不能用，请问有解决办法吗？

pip install 任何东西都会得到以下输出：

Exception:
Traceback (most recent call last):
File "C:\Python27\lib\site-packages\pip\basecommand.py", line 209, in main
status = self.run(options, args)
File "C:\Python27\lib\site-packages\pip\commands\install.py", line 299, in run
requirement_set.prepare_files(finder)
File "C:\Python27\lib\site-packages\pip\req\req_set.py", line 360, in prepare_files
ignore_dependencies=self.ignore_dependencies))
File "C:\Python27\lib\site-packages\pip\req\req_set.py", line 577, in _prepare_file
session=self.session, hashes=hashes)
File "C:\Python27\lib\site-packages\pip\download.py", line 810, in unpack_url
hashes=hashes
File "C:\Python27\lib\site-packages\pip\download.py", line 649, in unpack_http_url
hashes)
File "C:\Python27\lib\site-packages\pip\download.py", line 869, in _download_http_url
file_path = os.path.join(temp_dir, filename)
File "C:\Python27\lib\ntpath.py", line 85, in join
result_path = result_path + p_path
UnicodeDecodeError: 'ascii' codec can't decode byte 0xb2 in position 7: ordinal not in range(128)

python -m pip install --upgrade pip 也是一样，求解决办法