My new Vostro 3450 came with Trend Micro but after checking reviews I decided I' d like something better. A Dell technican that was working on another system told me that Microsoft Security Essentials is an excellent antivirus software. I have installed it and I noticed right away that performance is not compromised. Our other systems have Norton Internet Securty which at times takes a lot of CPU usage.

Should I run a scan from a different antivirus supplier occassionally? Microsoft recommends only running their Security Essentials and no other antivirus software. I use Ad Aware as well - should I uninstall it?