Hi Julie. I'm Greg, 10 years awarded Windows MVP, specializing in Installation, Performance, Troubleshooting and Activation, here to help you.
The certificate should be added when Kaspersky is installed. If not see how here:
https://support.kaspersky.com/us/14620
If you are in an organization that requires use of Kaspersky then I would consult your IT desk.
If this is your personal PC, I would NOT install Kaspersky or any 3rd party antivirus as this is the source of chronic problems in Windows. Instead I would use built-in Defender which gives adequate protection, best Windows performance, least issues, and is from Microsoft who knows how to protect their OS best.
If you want the best on-demand scanner install and run Malwarebytes free scanner. https://www.malwarebytes.com/mwb-download/. You can turn off the free trial in Account Settings to keep it only as a free scanner.
I hope it helps. Feel free to ask any questions.
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