Hi ephi_45 - To start out, are you running Windows 7 Professional, Ultimate, or Enterprise? These are the three editions that support a remote desktop connection.
If you are running one of these three editions, have you been able to connect in the past? Have you contacted the administrator?
While we are waiting for more information from you, you can take a look at these FAQs and see if they help - http://windows.microsoft.com/en-US/windows7/Remote-Desktop-Connection-frequently-asked-questions
Microsoft Windows Outreach