License key doesn't work and now avast! won't install?

I could not register my avast software through the program (said it couldn’t find the file?) so I filled out the web form and tried to use the license key that was emailed to me. When copy-pasted into my avast program, it told me it wasn’t a valid license key! I wasn’t sure how to repair, but I tried uninstalling and reinstalling and now avast won’t install at all. What do I do?

The date and time is correct, I’ve tried re-downloading the installer, and I can attach or copy-paste my setup log if need be.

I tried posting on another topic, but got no reply after I saw a “main man” posting responses. Any help would be appreciated. ???

(This is avast! Free Home edition, btw.)

but I tried uninstalling and reinstalling and now avast won't install at all
try running the uninstall tool first, and then install again http://www.avast.com/en-no/uninstall-utility and you have of course removed any previous used av program.....and used a removal tool to clear all leftovers http://uninstallers.blogspot.com/
I could not register my avast software through the program...........
Do you mean the keyless online reg ?

On-line registration is very simple and it’s the preferred method for all users of avast Free Antivirus 5.x installed on a computer with standard Internet connectivity. To perform on-line registration follow these steps:
http://support.avast.com/index.php?_m=knowledgebase&_a=viewarticle&kbarticleid=459

I did the online registration, but the license key it sent to my email wouldn’t work. It said it wasn’t a valid license key?

The online reg does not use a reg key, you fill out the form: Name and a valid E-mail address click OK and done

Please, upload (attach) the avast log: C:\Program Files\Alwil Software\Avast5\Setup\setup.log
(or the shorter C:\Users\All Users\Alwil Software\Avast5\log\Setup.log).

If the file is too big for the forum, post the last 400-500 lines of it.

FYI to all helpers: The OP has another thread and is also getting help here http://forum.avast.com/index.php?topic=74635.msg619976#msg619976. I alerted the OP to stick with one thread.