I am trying to install node_module but getting following error:
For example:npm install grunt-preprocess
D:\\grunt_pre>npm install grunt-preproces
The registry URL is pointing to https, you could try changing it by
npm config set registry="http://registry.npmjs.org/"
and then try installing the module. It may be possible that you are behind a proxy that is blocking secure (https) connections
If it doesn't work then may be you could manually try to download the current version of the module you are trying to install from the here
And run the command npm install grunt-preprocess-2.3.0.tgz