while (<DATA>) {
    print unless /(Everyone\s+R X|Webmins\s+all|Domain Admins\s+all|\s+o\s*\z)/;
}

__DATA__
wwwroot\development\images\_notes\homepage_area_68_f4.jpg.mno   Everyone                R X
wwwroot\development\images\_notes\homepage_area_68_f4.jpg.mno   Domain\Webmins          RWXD
wwwroot\development\images\_notes\homepage_area_68_f4.jpg.mno   Domain\Domain Admins    all
wwwroot\development\images\_notes\homepage_area_68_f4.jpg.mno   Domain\user             o