My on the network 10 PC… I am installed All Pc Avast Home Ed. Ver… But Avast, windows firewall services disabled. Uninstall avast, but not repair windows firewall… ! and not see on the network PC’s…
WHY WHY WHY
Avast doesn’t change a thing in a firewall, nor does it damage a firewall.
10 systems on 1 network doesn’t sound you have the rights to use Avast Home to me.
Do you use a server? If so, what OS?
All system Windows XP
Maybe you have some traces of some other antiviruses on your systems… most likely Norton or something similar.
10 PCs ? That doesn’t sound like home network… more like small business network. I am not sure you’re allowed to use avast! Home Edition (freeware) for business purposes.
Btw, avast! is not bad antivirus at all… just take a look at all other threads… so many very happy users that switched from all kind of other antivirus tools. That tells something 
Cheers !