How will you know if your PC is being hacked?

you should have a firewall, I used zonealarm but I switch to bitdfender total security suite... Zone alarm works and he will really pops up the intrusion coming from outside.. just in case if your not using the internet try to disable it for good and enable it when you will surf the net. put the network connection shortcut on your desktop screen to make it more accessible .. maybe that would help you prevent from being hacked.

Hackers have some tools to prevent being detected. In order your computer to be protected you must have a anti virus software and must have latest virus definition.

You need to install a good firewall to protect your system from any external attacks that might take place. There are various open source softwares that that might help. Some of them are Packet Filter and IP tables. Take care.