While I install Pymongo,Error shows that:

running install
running bdist_egg
running egg_info
writing pymongo.egg-info\PKG-INFO
writing top-level names to pymongo.egg-info\top_level.txt
writing dependency_links to pymongo.egg-info\dependency_links.txt
reading manifest file 'pymongo.egg-info\SOURCES.txt'
reading manifest template 'MANIFEST.in'
writing manifest file 'pymongo.egg-info\SOURCES.txt'
installing library code to build\bdist.win-amd64\egg
running install_lib
running build_py
running build_ext
building 'pymongo._cbson' extension
Traceback (most recent call last):
  File "setup.py", line 176, in <module>
    "doc": doc})
  File "C:\Python26\lib\distutils\core.py", line 152, in setup
    dist.run_commands()
  File "C:\Python26\lib\distutils\dist.py", line 975, in run_commands
    self.run_command(cmd)
  File "C:\Python26\lib\distutils\dist.py", line 995, in run_command
    cmd_obj.run()
  File "C:\Python26\lib\site-packages\setuptools-0.6c11-py2.6.egg\setuptools\command\install.py", line 76, in run
  File "C:\Python26\lib\site-packages\setuptools-0.6c11-py2.6.egg\setuptools\command\install.py", line 96, in do_egg_install
  File "C:\Python26\lib\distutils\cmd.py", line 333, in run_command
    self.distribution.run_command(command)
  File "C:\Python26\lib\distutils\dist.py", line 995, in run_command
    cmd_obj.run()
  File "C:\Python26\lib\site-packages\setuptools-0.6c11-py2.6.egg\setuptools\command\bdist_egg.py", line 175, in run
  File "C:\Python26\lib\site-packages\setuptools-0.6c11-py2.6.egg\setuptools\command\bdist_egg.py", line 161, in call_command
  File "C:\Python26\lib\distutils\cmd.py", line 333, in run_command
    self.distribution.run_command(command)
  File "C:\Python26\lib\distutils\dist.py", line 995, in run_command
    cmd_obj.run()
  File "C:\Python26\lib\site-packages\setuptools-0.6c11-py2.6.egg\setuptools\command\install_lib.py", line 20, in run
  File "C:\Python26\lib\distutils\command\install_lib.py", line 115, in build
    self.run_command('build_ext')
  File "C:\Python26\lib\distutils\cmd.py", line 333, in run_command
    self.distribution.run_command(command)
  File "C:\Python26\lib\distutils\dist.py", line 995, in run_command
    cmd_obj.run()
  File "setup.py", line 108, in run
    build_ext.run(self)
  File "C:\Python26\lib\distutils\command\build_ext.py", line 340, in run
    self.build_extensions()
  File "C:\Python26\lib\distutils\command\build_ext.py", line 449, in build_extensions
    self.build_extension(ext)
  File "setup.py", line 118, in build_extension
    build_ext.build_extension(self, ext)
  File "C:\Python26\lib\distutils\command\build_ext.py", line 499, in build_extension
    depends=ext.depends)
  File "C:\Python26\lib\distutils\msvc9compiler.py", line 449, in compile
    self.initialize()
  File "C:\Python26\lib\distutils\msvc9compiler.py", line 359, in initialize
    vc_env = query_vcvarsall(VERSION, plat_spec)
  File "C:\Python26\lib\distutils\msvc9compiler.py", line 275, in query_vcvarsall
    raise ValueError(str(list(result.keys())))
ValueError: [u'path']

There error info is same as Issue7511 .
Here is info about my machine:
OS: Windows Server 2008 R2(64bit)

I have installed both VS2010 and VS2008 in my machine.But VS2010 intalled before VS2008.
Also. I can found vcvars64.bat at dir:C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\bin\amd64, but i don't know why Python can't found it.

There is a temporarily way to avoid the error ,we can manual execute vcvars64.bat before intall python module, But I think it's a python bug.