My computer has been giving an odd messege for a month;
immediately windows o.s. has started the messege appears saying:
Errore durante l'avvio di msisv32.dll
Impossibile trovare il modulo specificato.
I don't know how to manage this thing, I hope it's not a virus.
Can somebody tell me something about this messege?
It could be an infection, so I moved this to that section just in case. That message could be simply indicating that something was uninstalled or maybe just moved from its default location and Windows is saying it can't find it, although as I can't find any information for that process I think you are wise to be suspicious.
Try running Stinger and the FREE version of Malwarebytes, both of which are linked off this page: https://community.mcafee.com/docs/DOC-2168
What is your operating system and service pack and are you totally up to date?