Avast free installation windows xp problem

[tantalan]

Hi I have a problem with installing avast free on my computer. I downloaded avast free form your website than i ran it and a window showed up with installation instructions, but after 3 seconds (before i could do anything) this window disappeared and nothing happens. Do you know where is the problem? Is it that i use windows xp?
I used older versions of avast and everytime everything was fine and it worked well. I must say that io have completely new installation of windows xp sp3. No other programs installed. Thanks.

[Lisandro]

When the window disappears, is there a log?
If so, please, upload (attach) the avast log:
<avast folder>\Setup\setup.log

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