Ok I can only help by telling you what can be done here!
See Nmap scan you are using not only give results for port scans. It does hell lots of things!
Ok so now scan for the version of the open port via nmap. Yes it also give results to get the version. So now you got the version. Google the exploit of the version the server is running! You might not get much but dig and see if you get something! There are many ways to hack into a box.
Also see the version server is running. Google for the exploit of the server version, try your luck there too. See if any misconfigured file there on the server! Its a Windows server I guess so msf will help you if you use it correctly!
Best Luck pal (Y) A cookie please, if you find this informative!