lets say u have a 4.8 Pro license, how wuld u get that into a license file?
I don’t know how Pro works, but when I installed the free version it took my license information and automatically put it into the new installation. I suspect the registration keys are stored in the Windows registry and not a file.
The IS requires a license file. Not sure about Pro version.
of course it does, its not free after all.
You just need to install the new avast! Pro 5 over the existing 4.8 Pro installation . The license should be automatically converted into v 5 license 
personally i always do clean installations and was looking for how it is done that way.
I have hit the same problem on my Vista partition. I had Pro there downloaded Avast 5, it would not overwrite 4.8 and I was required to run Aswclear to enable it to install. Now I can find no way of inserting my licence code… Is there the ability to mail my code to Avast and for them to send me a licence file for the new version in return ?
I had that issue, why is not a way to insert v4.8 key on v5?? I had to downgrade to 4.8
Well you can request a license file with your current 4.8 Pro key here - http://www.avast.com/resend-license.php
After clicking ‘purchase now’, new windows should appear where you can click ‘i have already license’ or soemthing similar, then you’ll be asked for your email and you’ll be sent you license file.
Btw when installing v5 over v4, setup will fully remove v4, so no need to worry about problems caused by some remains of v4.
Well, actually, the upgrade doesnt do it well on my machine: in this post http://forum.avast.com/index.php?topic=53692.0 u can see my setup debug, and a recording from my installation steps. Iam online on the entire process. I have alredy installed Free Version. I dont know why the free version installs excellent and the pro version keeps freezing my pc and blocking my internet access. WTF is going on??
I don’t know either. The button on v5 give me link to: http://www.avast.com/go.php?verb=resend-license, but the site said it is a restricted site, I need to give username and password. But with no furtune I would understand what it means 
I did that and it said there was a problem with my email address. Shouldn’t be so I’m waiting for Vlk to help me in the morning.
I have wasted so long trying to sort out getting a license file.
Purchases Avast Pro 4 on 17th July 2009 - when requesting file using licence key - I get an email back saying
Dear customer,
we are sorry, but our records show no valid purchases
with the e-mail address you specified.
Please make sure the information you supplied is correct, and
the original purchase was carried out using this email address.
I have emails to prove I purchased it!
Any suggestions
This is driving me mad.
I also have “service stopped” “avast detected that your main shield is turned off”
I can’t turn it on…
Try to use “trial license” for moment till the problem solved.
Where you bought the license? From reseller? You may contact them again to verified this issue.
Hello,
I have the same problem. I have a avast 4.8 Professional license purchased on eBay. Now I can perform under http://www.avast.com/resend-license.php no conversion to Avast 5:
Dear customer,we are sorry, but our records show no valid purchases with the e-mail address you specified.
Please make sure the information you supplied is correct, and the original purchase was carried out using this email address.
There is no way that this license with Avast using 5 to. ???
You bought it on eBay…?
Hmm, then you might have actually become a victim of a software pirate :-\
We have seen some pirates selling illegal (pirated) copies of avast Pro on eBay in the past…
Thanks
Vlk
Is there a way to check whether my license is a pirated copy?
You can post the license key - I mean the part before the dash character.