Doesn't detect most of the common virii running rampant in most of my client's work environments. Most of them had purchased Avast Pro from us. In one of those bizarre instances, work had stalled on many machines in a single work environment because Avast was detecting a virus (forgot name) on all pen drives being attached and prompting for user action. It was perpetual in the sense that all the host machines were themselves infected (which obviously Avast did not detect) and was re-infecting the drives as soon as Avast cleaned the drive
! That one instance cost me a hell lotta time to fix. And that after convincing my clients to upgrade from pirated Nortons to paid Avast :no:!