It would depend on the certificate each one uses. If you open MMC, Go to File-> Add Snap-In, Select Certificates, then do Machine Account, This machine, you can see all the certificates the machine trusts. You can also go through the same produce, but choose service account, and select the avast related stuff, and check those certificates. I'm no expert on certificates, but I can usually muddle my way through. On my systems, I can't seem to find much that is helpful.