Because of it, I can't add/ create new secret key.
Please advise.
C:\GNUPG>gpg --update-trustdb
gpg: renaming C:/GnuPG\pubring.gpg' to C:/GnuPG\pubring.bak' failed:
Permission denied
gpg: failed to rebuild keyring cache: file rename error
gpg: 3 marginal(s) needed, 1 complete(s) needed, classic trust model
gpg: depth: 0 valid: 9 signed: 3 trust: 0-, 0q, 0n, 0m, 0f, 9u
gpg: depth: 1 valid: 3 signed: 0 trust: 0-, 0q, 0n, 0m, 3f, 0u
gpg: next trustdb check due at 2016-04-22