3

Can you try to repair your installation?
Yes. and reboot again and nothing.
Then install and reinstall and nothing: every time the Avast service appear “Disabled”.

I change my version of avast: from spanish versión to english version and still the same problem.

Do you have any other antivirus installed in your computer?

Nop. Using Avast for 3 or 4 years.

Do you use a firewall? Which one?
No. I not use any one.

Also, take a look into Administrative Tools > Services

They are set “Disable”. If I do it automatically, sometimes starts and other Windows XP get the error message: “Error 108”.