While Microsoft Safety Scanner can be a useful tool for identifying malware problems on a computer and resolving some of them, Microsoft does not advise using the tool as a user’s only protection against malware.

Microsoft Safety Scanner Lacks Real-Time Anti-Malware Protection Microsoft Safety Scanner has a unique characteristic in that it expires ten days after being downloaded, so users will need to download and run the tool again if they want to run a new scan or get the latest anti-malware definitions for Safety Scanner. Microsoft Safety Scanner can be downloaded through Microsoft’s Safety and Security Center web site, which also provides the latest service packs, drivers, security patches and other updates for Microsoft software to help users stay current on the latest security issues. The Safety Scanner tool additionally offers the capability to remove some forms of malware. Microsoft Safety Scanner is a free security tool that provides on-demand scanning for viruses, spyware and other malicious software.

Microsoft safety scanner web page