To export your private keys you can make use of the commandline tool from GPG.
First run ‘cmd’ with the following command: ‘gpg --list-secret-keys‘. This will list all available keys of the current user. Now you have to find the desired key. Look at the second part of the second column, there you can spot something like ‘2048R/3210C567‘, the number behind the slash (/) is the key-id.
To export the desired key run ‘gpg --export-secret-keys‘ with the ‘-a‘ flag, followed by the ‘key-id‘ of your specific key, followed by the ‘>‘, again followed by a filename like ‘private.asc‘ to pass all output to this file.
Example:
gpg –export-secret-keys -a 3210C567 > \path\private.asc
Notes:
'gpg --export-secret-keys'by its own dumps all keys to the windows shell'-a'outputs a ascii armored version instead of a binary'key-id'a unique number to target the desired key only'>'redirects the output to a text file