Does a typical computer begin with any shared secret with a certificate authority when I buy it? If not, a compromised home router could fake everything and get my credit card info when I attempt to buy something, even if I were careful to use https.
I assume your question was:
Does a computer ship with CA certificates preinstalled?
This is the case.
The standard OEM installation of Windows (and all other OS) on a computer ships with a preinstalled list of trusted certificates.
Even if you had CA certificates in your store that were preinstalled, they don't come there from nowhere. Windows updates the preinstalled list through Windows Updater. The connection to microsoft is also encrypted, so that you can trust the updates to be from microsoft.