What is the least intrusive and most effective antivirus software for a Windows PC that is used for software development (lots of small files and lots of disk I/O)? The software should support running from the command line so that virus scan be included into the build process. Edit: I understand that prevention techniques work better than any antivirus, but the employer demands that commercial AV software be used in the development environment (looking a replacement for horrible Symantec Antivirus).