You first have to import the signing key first. In this case, import:
-----BEGIN PGP PUBLIC KEY BLOCK-----
Version: SKS 1.1.3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=T2Ag
-----END PGP PUBLIC KEY BLOCK-----
then use the file manager in gpg4win to verify the file.