Use this command line to decrypt using gpg4win commandline gpg.exe
echo yourpassphrase|gpg.exe --batch --yes --passphrase-fd 0 -o "d:\outputfile.txt" --decrypt "d:\outputfile.txt.gpg"
Options
--batch: Use batch mode. Never ask, do not allow interactive commands.
--passphrase-fd n: Read the passphrase from file descriptor n. If you use 0 for n, the passphrase will be read from stdin. This can only be used if only one passphrase is supplied.
-o: output file name
--decrypt: decrypt file name