2. Do you remember making any changes to the computer prior to this issue?
3. Do you receive any error codes or messages?
You can try the methods below and check the results:
a. Check if the below settings in windows security center:
b. To specify that you're using an antivirus program that Windows does not find
c. Click Start and then click Control Panel.
d. Double-click Security Center.
e. In the Security Center, under Virus Protection, check if “I have antivirus software that I'll monitor myself” is turned on.
Note: You should only disable these alerts if you are sure that your computer is protected by the full version of an up-to-date antivirus program. In addition, once you disable alerts, even if your program receives an update that makes it fully detected
within Security Center, you will not receive alerts unless you clear this check box.
You can try to rebuild the repository folder and then check the result
a. Click the start button and type cmd in start search.
b. Right click on cmd and select "run as administrator".
c. In the command window at the prompt type the following commands and press Enter:
net stop winmgmt
ren repository repository.old
net start winmgmt
d. Restart the computer and check the result.
You can also refer the following link and try downloading the Microsoft Safety Scanner and perform a full scan on your computer and check.