Notes about the P7C file extension:
To open this file type, a required software must be installed. Without it you only see a Windows message "The following file cannot be opened
" (Windows 7) or "How do you want to open this file?
" (Windows 10) if you double-click the file. There click on "More apps"
and choose a suitable software to view such files on your PC or from email attachments.
The P7C file type is primarily associated with 'PKCS #7 Certificate'. In cryptography, a public key certificate (or identity certificate) is a certificate which uses a digital signature to bind together a public key with an identity. The certificate can be used to verify that a public key belongs to an individual. See Section 3.2 in RFC 2311. (Degenerate signedData certs-only message.)
Detailed information for file extension P7C:
Mime type: application/pkcs7-mime, application/x-pkcs7-mime, application/keychain_access
To change file associations press Windows Key
and then Apps and Features
> Default apps
> Choose default apps by file type
Invalid file associations could be the result of underlying issues within your Windows PC.