If your laptop is running Windows Vista or higher, please use Microsoft Security Essentials. 3rd party AV is asking for trouble. Also, please be sure to make the proper exclusions, no matter what you decide, for directories, file types, etc. AV kills performance when improperly configured. I would personally go so far to argue that it just doesn't belong on critical equipment which should not be used for general purpose computing. That said, there is a happy in-between', as I said, be sure to properly configure what ever you use. There is no install and forget it solution if you want to keep peak performance *and* use the AV solution real-time. Best of luck.