First you will need to download Gpg4win (https://www.gpg4win.org/index.html) and run the installer, you will be asked to choose what additional components to install, ensure the following is selected (as they are by default);
The installation should only take a minute or so, once completed you will notice a program called Kleopatra has been installed. This is the GUI in which you will handle all of your PGP tasks. You may notice an icon in your taskbar, it is a lady with a red wig.
Let's send our first encrypted message, first we are going to need somebody to talk to. I guess for this example we can assume you're about to send your address to a vendor. On the order page, copy the public key to your clipboard.
Once their key is contained within your clipboard, right click the Kleopatra icon located in your task (lady with a red wig) and then select certificate import.
On the next screen, ensure the checkbox is selected and click certify.
If everything worked out you will see a window stating the certificate was imported successfully.
Now we need to prepare the message, so in this case it will be your address. Open up a fresh notepad document and type in your correctly formatted address and any additional information. Once done, copy the entire message to your clipboard.
Head back to the Kleopatra icon in the taskboard, right click the icon, select clipboard, and then finally encrypt.
Select the recipient that you intend to send the message to, as we imported their public key they will be somewhere in your list. Please note if you use a Live OS and have no persistent storage configured you will need to re-import contacts each time you restart your computer or virtual machine. Once your recipient has been selected, click next.
If all is well, you will see a screen stating that the encryption succeeded. Great!
Now all you need to do is go back into a fresh notepad, click paste, and then your encrypted message is ready to be sent to the vendor.
Copy the message you want to decrypt and then in your system tray right click on the Kleopatra icon > Clipboard > Decrypt / Verify, when asked enter your PGP key password and the decrypted message will be copied to your clipboard.