If u're using AVG anti-virus and have failed to update it bcoz u've received the message

Invalid Update Control CTC File

Go to

C:\Documents and Settings\All Users\Application Data\avg8\update\download

and delete files with .ctf extension

If I'm not mistaken, there're 2 files with .ctf extension - "avginfoavi.ctf" and "avginfowin.ctf"

Then try updating ur avg again. Should work =)

Random random random...