Looks like Mel got your support e-mail. You can always go to stardock.com/support and have the information sent to you. You can also log in here:
WC Registrations
To get all your registration info (this is good if you think you may have spam filters blocking our e-mails). Other than that, you should be able to log into Impulse and have everything show up for you. The software will be listed under the "My Desktop" tab. As a dial-up user, Impulse is a good thing to have around, as it's actually getting you compressed install information, so less downloading. Also, if updates are avaiable, Impulse will only grab the files needed to be updated, and not the whole application, again saving on download time. Finally, if something should happen during the download, Impulse will let you resume it, so no wasted time downloading information you already have. If you REALLY do not want to have Impulse installed, once you have WindowBlinds downloaded and installed you can remove it, but I would highly recommend keeping it around.