pip install出错：Cannot connect to proxy

pip install *** :Cannot connect to proxy

在使用pip install 安装任何新的包都会出现下面错误：

PS C:\WINDOWS\system32> pip install django
Looking in indexes: http://pypi.douban.com/simple
Collecting django
  Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'ProxyError('Cannot connect to proxy.', 
  NewConnectionError('._vendor.urllib3.connection.HTTPConnection object at 0x000002574165FF60>: Failed to establish a new connection: [WinError 10061] 由于目标计算机积极拒绝，无法连接。',))': 
  http://pypi.douban.com/simple/django/
  
  Retrying (Retry(total=3, connect=None, read=None, redirect=None, status=None)) after connection broken by 'ProxyError('Cannot connect to proxy.', 
  NewConnectionError('._vendor.urllib3.connection.HTTPConnection object at 0x000002574165F128>: Failed to establish a new connection: [WinError 10061] 由于目标计算机积极拒绝，无法连接。',))': 
  http://pypi.douban.com/simple/django/
  
  Retrying (Retry(total=2, connect=None, read=None, redirect=None, status=None)) after connection broken by 'ProxyError('Cannot connect to proxy.', 
  NewConnectionError('._vendor.urllib3.connection.HTTPConnection object at 0x0000025741663208>: Failed to establish a new connection: [WinError 10061] 由于目标计算机积极拒绝，无法连接。',))': 
  http://pypi.douban.com/simple/django/
  
  Retrying (Retry(total=1, connect=None, read=None, redirect=None, status=None)) after connection broken by 'ProxyError('Cannot connect to proxy.', 
  NewConnectionError('._vendor.urllib3.connection.HTTPConnection object at 0x0000025741663358>: Failed to establish a new connection: [WinError 10061] 由于目标计算机积极拒绝，无法连接。',))': 
  http://pypi.douban.com/simple/django/
  
  Retrying (Retry(total=0, connect=None, read=None, redirect=None, status=None)) after connection broken by 'ProxyError('Cannot connect to proxy.', 
  NewConnectionError('._vendor.urllib3.connection.HTTPConnection object at 0x00000257416630F0>: Failed to establish a new connection: [WinError 10061] 由于目标计算机积极拒绝，无法连接。',))': 
  http://pypi.douban.com/simple/django/
  
  Could not find a version that satisfies the requirement django (from versions: )
No matching distribution found for django

出现这样的问题的原因是代理出现了问题，安装了蓝灯出现的。只要关闭蓝灯， pip install 就会提示上面的bug。

解决办法：

按Win+R快捷键，输入regedit，打开注册表编辑器找到HKEY_CURRENT_USER/Software/Microsoft/Windows/CurrentVersion/Internet Settings分支，把它下面以 Proxy 打头的键值对（如ProxyEnable，ProxyOverride，ProxyServer等）全部删除。

这样再次 pip install 就可以了。