用npm命令，在win7 64位系统下安装mongodb，总出现这样的报错：
。。。。。
206 error bson@0.1.8 install: (node-gyp rebuild 2> builderror.log) || (exit 0)
206 error spawn ENOENT
207 error Failed at the bson@0.1.8 install script.
207 error This is most likely a problem with the bson package,
207 error not with npm itself.
207 error Tell the author that this fails on your system:
207 error (node-gyp rebuild 2> builderror.log) || (exit 0)
207 error You can get their info via:
207 error npm owner ls bson
。。。。。
但是直接下载安装mongo压缩包，单独启动，可以启动成功。
郁闷中。。。 有人知道是怎么回事吗
