I receintly started having a problem with the AVG Internet Security 2012 firewall and am wondering if there may be a connection to the receint VMWare Workstation update. This is on a Windows 7 64 Bit system.
When installing an update to AVG 2012 it complains about a driver it's installing not being "digitally signed". This is the "AVG network filter driver", which AVG swears is properly signed. It does, however, install the driver (even though the windows message was that it wasn't going to), but then it totally stops all network connectivity to the system, not just the virtual machines. AVG 2012 also complains that there's an "!Error" with the firewall and that the firewall is "Not available". Only by turning off those drivers in the network adapter settings can I get connectivity back to the system.
So, I'm kind of fishing here. AVG has so far been unable to figure this problem out. About the only thing that's changed receintly on my system has been the VMWare update to 8.0.1 build-528992. I think I'll take some time to un-install VMWare and see if that helps, but am interested in whether anyone else has seen this.
64-bit Windows does not run drivers that aren't signed. That sounds entirely like an AVG problem. If you browse to the .sys file in Explorer, right-click it and view its properties, you can check that the signature is valid.
Thanks for your suggestion to check the sys file directly. I did and it does say it has a valid certificate to "AVG Technologies" by "VeriSign Class 3 Code Signing 2009-2 CA" valid from 2/16/2010 to 3/5/2012. So should be valid. That is the driver for which I get the alert box, unless there's some kind of alternate store thing with Windows 7 (can't remember what that's called) that I missed. I did a search on the entire drive for that driver file and purged all copies when I did a full un-install of AVG a couple days ago, so I'm a bit miffed on this.
In any case, I uninstalled VMWare Workstation yesterday and the Akamai Netsession Interface that was also installed earlier last month (the only other recient network related change) and tried AVG firewall again with the same sad results. Unless there's something left behind by VMWare, the problem isn't a VMWare concern (marked this thread as Answered).
Still waiting to hear back from AVG on my diagnostic dump to them.