Too add a bit further ot the above.
If you need to establish which port and application is running etc.
Try start/run type in command to get you to a dos window.
Then type - netstat -anon
From that list you will PID Numbers.
Leave the dos window open with the list goto control alt delete and task manager click on processes then the view tab then select columns and place tick in PID.
You can then cross reference from the dos window which PID is using which application.
As mentioned above then you can try eliminating to see if any are causing the port to remain open.
