Can't Activate Avast

Avast Free Antivirus / Premium Security
1

I renewed my Avast but it won’t install. Is it because I am still using XP?
When I press Insert Licence Key I get a window saying it has been successfully installed, but the Avast icon has a big X through it indicating that I have not got the new licence.
I then get a window that says it is updating my Avast, but nothing happens. It gets stuck on Step 1 of 3 steps. The message is "Initializing Please Wait’. I have been waiting for more than a day. What should I do please?

2
  • Which Avast…? (Free/Pro/IS/Premier)
  • Which version…?
  • OS…? (32/64 Bit…? - which SP…?)
  • Other security related software installed…?
  • Which AV(s) did you use before Avast…?