Unable to install avast 4 professional edition

[useless]

This is a mess.  On 10th January i purchased avast 4 professional edition.  I downloaded it and double clicked on it.  The avast message box came up and i clicked continue.  It looked like it was installing - took about 10 seconds and only got as far as VPS and said it had finished so i clicked finish.  My computer didnt restart and it hasn't been installed.  I tried a few more times but still it would not install.  So I thought i had better install the free version as a only have a few days left with the free editon.  which i think i have as now as later on when i tried to install the professional edition download the avast home edition installs instead.  I've tried entering the registration key i got for the professional edition in the home edition it won't accept it.

I'm at a complete loss.  Can anyone please advise me how i can install the professional edition?
   

[wsenese]

I'm also having problems with installing
Have you learned any more on how to resolve?

[Neo1]

hello, make sure your comp is up to date with windows updates, try using the avast uninstaller "http://www.avast.com/uninstall-utility" to remove avast home edition, restart try installing avast 4.8 pro again and maybe "run as administrator" depending if you have admin privileges or not........hope it helps

[REDACTED]

I am having the same problem loading on to my new cp. can`t even get tec. support! I still have 3.5 yeats on my license.