NIS 2011 causing lag in games

Hi,

 

I'm currently experiencing lag spikes as I play games (Counter Strike, Heroes of Newerth). I'm almost 100% sure that NIS 2011 is the cause of the lag because I have it installed on 3 PCs and they all lag the same way. I'm sure it's not my internet, because I've had multiple friends over who've used my internet to game and have had no problems whatsover.

 

I've searched around the forums and the net, and the most common solution was to turn on Silent Mode. However, this hasn't worked for me and I'm still experiencing lag spikes.

 

Any help would be appreciated. Thanks.