Well to start with Avast Program support for XP and Vista has ceased the last supported program version is 18.8.2356 (but some have had issues with this version, me for one). However if you have this version virus definition updates are still supported.
The avast web browser is no more, it is a new product called Avast Secure Browser, the only problem with that is it isn't compatible with XP.
I would suggest that you remove your email address:
1. Support is only given in the forums not by email.
2. It is a public forum and it could be harvested by a spam bot.