it can't be bad saved documents because before we installed avast all of these files did work.
Ok, so it was not avast...
avast did not touch/change the doc files unless they were infected and you intentionally make (choose) avast to delete all macros of it. The Home version does not have an automated feature to do this job. If avast detect them, they should have order avast to do something...
You mean avast can locate bad saved document?
No it cannot do it... only if avast cannot 'read' you should be warned (file error).
How is it possible that word dont save documents correctly? how can i fix it?
Disk errors, power failure, CDRW troubles... a lot of possibilities. None of them related to avast in my opinion.
To fix, run scandisk (right click the HDD icon, properties, tools, verify disk...)