Hi Guys and Gals!

Newb here so thanks for your patience and help.

I have a simple audio recording program I have a microphone connected to outside of my house because the one built-in my security cam does a poor job. In my security program I have the option to pick which microphone to record from as its recording video. Works fine most of time however every now and then I will play back a short video captured and there will be no sound. I then check the microphone setting and the record volume will be at zero. I always set this at 75% record volume level and never change it. I might be paranoid but I think someone is hacking into my computer and changing this setting. My question in a nutshell is how can I tell if this is happening or what network tool do I need to use to find out?

fyi...........I would be less inclined to think this was happening but for the fact my house was broken into one night when I was away and nothing was stolen. Also have reason to believe it was one of my neighbors.

Need peace of mind so anyway you can help will be much appreciated.

Custom build computer MSI N970-G65 mobo
AMD Phenom II x 4 965 processor
Win 7 Pro OEM install

I use Chrome for browser
Comcast is my isp avg 75mbps down
I use the Comcast provide N360 Norten Security Suite and it list any intrusion attempts (that it blocks) in a monthy report and when it does its usually a windows .exe causing it.

Thanks againi