vista service pack 1 and avast

hi
i m using windows vista home premium and avast
when i installed service pack 1 after that my avast wont start at all.
when i start any scan it says Initializing engine, please wait…
and it does not start at all.
what is the problem
my avast is up to date
pls reply

  1. Repair avast by going Add and Remove Programs>Avast(scroll down if you cant
    find it)

    2.If the repair doesn’t fix the problem then Uninstall
    avast>Reboot>Reinstall>Reboot

did you download the actual installation program (4.8.1201)

this is a problem which should be solved in the actual program version…

to download go to:
http://avast.com/eng/programs.html

thanks guys
my problem has been resolved now
i just restarted my windows. it was all abck to normal again.
i dnt knw how it worked but it did anyhow.
thank u guys for ur support.
can anyone tell how to get rid of yahoo messenger virus which sends weard links to friendlist without our knowledge.
thanks