I have a file that is compressed. I used a program to find out what kind of file it is and it says that it's a gpg file. How do you uncompress a gpg file?
GPG is a free implementation of the OpenPGP standard: http://www.gnupg.org
It is used to encrypt and sign files not to compress them.
You do not state which system you are using but Google will help to find a free GPG implementation for your platform.
If you are using Linux you can for example:
$ gpg --output destination --decrypt sourcefile.gpg
but you will need the proper key.
If I recall completely, a '
gpg' file is encrypted rather than compressed.
What you need to do is use the gnupg tool to decrypt it -- of course using a key.
Or, its the security key file itself. In which case there is not data here, just the key to decrypt other encrypted data.
The decrypted file may then itself be compressed/archived in some other format,
which can be used to open its contents.