执行pip安装其他模块时，提示Unknown or unsupported command 'install'

问题：执行pip安装其他模块时，提示Unknown or unsupported command 'install'
解决方法：
1.使用命令检查pip装在哪里
C:\>where pip
结果返回：
C:\strawberry\perl\bin\pip
C:\strawberry\perl\bin\pip.bat
C:\Python27\Scripts\pip.exe
2.通过控制面板删除strawberry


3.再执行pip install -U robotframework-requests
过程如下：
Retrying (Retry(total=4, connect=None, read=None, redirect=None)) after connecti
on broken by 'ProtocolError('Connection aborted.', error(10053, ''))': /simple/r
obotframework-requests/
Collecting robotframework-requests
  Downloading robotframework-requests-0.4.5.tar.gz
Installing collected packages: robotframework-requests
  Found existing installation: robotframework-requests 0.3.7
    DEPRECATION: Uninstalling a distutils installed project (robotframework-requ
ests) has been deprecated and will be removed in a future version. This is due t
o the fact that uninstalling a distutils project will only partially uninstall t
he project.
    Uninstalling robotframework-requests-0.3.7:
      Successfully uninstalled robotframework-requests-0.3.7
  Running setup.py install for robotframework-requests ... done
Successfully installed robotframework-requests-0.4.5
安装成功