Avast! I've changed me virus scanner ye swabs!

[Skywing]

I just don't run programs I don't trust and operate without A/V. (Virtually any A/V program you pick up off the shelf is going to introduce myriad security and stability issues due to ill-advised hooks and the like, in my experience.)

Then again, most folks are not so paranoid about only executing programs from trusted sources, so YMMV:)