I’ve tried downloading several times, from Firewall Download | Best Firewall Security software for Windows and Download Antivirus for Mac | Free Antivirus Software for Mac but when I try to upgrade the firewall from 3 to 4, I get “image signature verification failed”. Found another thread, but it seemed related to 64 bit install. I’m on Vista (32 bit).
Are you running the installer from the same physical drive you are installing to?
If not, this can cause the error you mention.
Hope this helps.
No, there is only one hard drive on the laptop with the issue. There is peer-to-peer mapped drive there, but it is not being run from or installed to it.