How to install gnupg-2.0.18 and decrypt gpg files

[Robert J. Hansen]

> I have downloaded gnupg-2.0.18 to decrypt some files formatted .gz.gpg
> (e.g. 70195_B11_WTCCCT444825.CEL.gz.gpg).

You appear to have downloaded a package containing the GnuPG source code,
not the GnuPG executables.

If you go to http://www.gpg4win.org, you will be able to download the
GnuPG executables.  These work well with Windows 7: I've used them
successfully on Win7 and Win7/64.

Good luck!