Microsoft Malicious Software Removal Tool is an anti-malware utility that checks computers running Windows 10 Technical Preview, Windows 8 and Windows 8.1, Windows 7, Windows Vista, Windows XP*, Windows Server 2012 R2 and Windows Server 2012, Windows Server 2008, and Windows Server 2003 for infections by specific, prevalent malicious software – including Blaster, Sasser, and Mydoom – and helps remove malware and any other infections found.