I have a Win 7 Professional, with 8 GB Ram which I have been using for the last 10 years. Ever since I have owned this Laptop, I have  been using Microsoft Security Essentials  as my anti-virus. Till 2nd February 2021, I have had no   issues with M S E which updates and scans my Laptop  around 06:00 A.M. on a daily basis.

From 3rd February 2021,  I have noticed that MSE has been updating and scanning my Laptop atleast three times a day against the norm of once every  24 hours. I found this very strange. I wish to point out that I have made no changes  on my Laptop. The only thing I suspect is that this has started only after the Engine number has changed  as under :

Upto 2nd February, 2021 Previous Engine Version was 1.1.17700.4

3rd February 2021 onwards Updated Engine Version is : 1.1.17800.5

MSE, now it seems has been updating definitions and scanning computers on a random basis. I also wish to add that  if my Laptop is not connected to the Internet and MSE  decides to update  definitions at that time, an error is reported as under : 

Event ID:      2001 Microsoft Antimalware has encountered an error trying to update signatures.

***Moved from: Virus and Malware / Microsoft Security Essentials / Updating virus and spyware definitions / Windows 7***