What was the exact error on the BSOD?
Do you have another av on those systems as well?
- If so which one?
- If not, was there one on previously? (which one)
Any error(s) in Avast's log files?
connections to servers failing
Did you allow ashwebsv in your firewall?
connections to servers failing, mail not able to be sent
What happen if you tried?
Any error? If so which one?
Are these preinstalled OS's?
Any other (resident?) security related software installed?