Open/Closed Ports

Can anyone reccomend a utility that manages ports in Windows 7? The long and the short of it, I believe I may have some nasty malware or a keylogger on my PC. I've run the usual programs such as McAfee, CCleaner, Malwarebytes, and Adaware and none of these programs have found either a virus, trojan, worm, or other nefarious code. What I do know is that my email account has sent out spam on a couple of occasions.  Yes I've changed my passwords and cleaned out the IE cache.  I have also noted that my PC is hanging up more often than it has in the past.

In trying to investigate this problem, I was surprised to see the number of open ports through my firewall and many of them are unknown. I have been playing around with NirSoft and their little app called CurrPorts.  It is interesting to see which ports are active and or listening but unfortunately I don't know what these ports are for?  I also would think that a keylogger is using one of them.  If I could identify and close these ports... well that would be nice.

Any advice would be appriciated. I really want to avoid a complete re-install if at all possible