How do I use gpg to decrypt encrypted files????

[BosseB]

I have a number of encrypted files, which I need to decrypt. I have
installed GPG 1.4.9 on my Windows XP-Pro SP3 PC. I have the necessary
keyrings and they work with Thunderbird and Enigmail.

But as I said I need to decrypt files that are on my hard disk, not in
an email....

I tried this command in a command window:
 gpg -d <asc filename>
I got a prompt for my passphrase and as soon as I entered this the
window filled with large amounts of strange characters and the PC
speaker started to beep and never would stop.
I finally had to use ProcessExplorer and kill the cmd process to get
silence. :-(

What is the correct procedure to decrypt a file thta has been
encrypted with my public key?
And is there no way to use some kind of GUI tool to do this so the
masses of option codes are automatically used?

-- 
Bo Berglund
Developer in Sweden