What’s the difference between Microsoft Security, MSRT and MSERT?


Sep 11, 2011
What’s the difference between Microsoft Security (Windows Defender) / Windows Malicious Software Removal Tool (MSRT) and Microsoft Safety Scanner?

I’ve been looking at the Microsoft articles on these tools and some posts I googled. I’m still confused about when I should use these in real case scenarios (for a computer repair technician).

I’d love to hear opinions on when to use these tools. My assumption was that Windows Defender was enough.

Any advice much welcome

Math Geek

windows defender is a real time program that monitors what you do actively looking for possible threats. these are not just signature based but also calls on MS AI to help decide if something looks malicious or dangerous. it runs in the background and is always on the lookout. this should stay running 24/7 as long as the pc is in use.

MSRT and safety scanner are fairly similar in that they look for specific threats based on a library of signatures. but there are distinct differences

MSRT doc says this
"The tool removes only specific prevalent malicious software. Specific prevalent malicious software is a small subset of all the malicious software that exists today.
The tool focuses on the detection and removal of active malicious software. Active malicious software is malicious software that is currently running on the computer. The tool cannot remove malicious software that is not running. However, an antivirus product can perform this task. "

while security scanner says this
"Safety Scanner only scans when manually triggered and is available for use 10 days after being downloaded. We recommend that you always download the latest version of this tool before each scan."

so MSRT works on ACTIVELY running malware and it looks like the security scanner is aimed at recent and current trends. it expires rapidly as is updated regularly it seems but is not designed to handle every threat known. that's more like what a program like malware bites is designed to do.