Step 1: Download a cURL for Windows from http://curl.haxx.se/download.html
Step 2: Execute cURL command as described in GitHub’s blog post Git.io: GitHub URL Shortener
curl -i http://git.io -F "url=@TARGET_URL" -F "code=@SHORT_CODE"
The command is pretty straight forward. Remember to replace @TARGET_URL with the desired destination and @SHORT_CODE with the preferred short code.
Check out mine at http://git.io/dn