Find out which processes are running, and what software is making out-going connections from your PC

Right click start bar -> Start Task Manager -> Select Performance Tab -> Click the "Resource Monitor" button at the bottom

In the Resource monitor, click the Overview Tab

This shows all running processes in the CPU section

All network connections are show in the Network tab

Now, in your in terminal: (start -> run -> type "cmd" hit enter)

in one window type: netstat -abfo 5

in another window, type: tasklist /svc

now correlate that info with the resource monitor, hit google for any unknown or suspicious signs, and you should finish up knowing a lot more about whats happening on your pc :)