Windows: Cannot login in to a server through RDC

Issue:
Cannot login in to a server through Remote Desktop connection

Other Symptoms:
Upon logging in, an error saying 'Maximum users exceeded' is being displayed

Resolution:

1. Go to command priompt
2. Type 'mstsc /console', RDC window will appear
   
3. Enter server name and login
   
4. Open taskmgr
5. Go to users
6. Logoff users to free up