Taking Intranet screenshots or taking screenshot of websites on localhost is more complicated than taking
a screenshot of a normal website on the web.
For internal websites that don't have absolute URLs pointing to any resources that is not accessible
on the Internet and for websites that you don't mind opening the up to the Internet the simplest option would be to set up port forwarding to your internal website.
You would need log in to your server and add a port forward to the computer that hosts your website. You then need to configure your web server to accept calls on the port you are forwarding over.
For instance if your router IP address is 126.96.36.199 you could add a port forwarding for port 12345 to the computer that hosts the website and add this port to your web server configuration as one of the ports it listens on.
Please do not ask us how to do this, information on configuring your web server and router should be available on the internet.
http://188.8.131.52:12345/mypage.html should work externally.
Alternatively if you only want to open up your internal websites to GrabzIt's servers or if you want to capture content that references resources only accessible on your intranet you can use the GrabzIt IntraProxy.