Please, give us more information: your OS, firewall, proxy and spywares...
Can you 'start' avast?
Are the providers (residents) running? What do you see when you put the mouse over the 'a' icon at the system tray?
Have you boot after installation?
Could you run Mail Protection Wizard from Start Menu (avast! folder)?
If you give us more information, certainly you´ll have your system working again... Although you just do not remember your email username and/or password... If this happen, tell us and we can guide you 'back', before avast! installation and then install avast! and have your e-mail accounts configurated.
