How can I disable Windows Firewall?

Question

Windows 7, 8.1

I get an exception when I try to disable Windows Firewall. I try to do it with admin rights. But I haven't the same problem for Windows Firewall enabling.

Type NetFwMgrType = Type.GetTypeFromProgID("HNetCfg.FwMgr", false);
INetFwMgr mgr = (INetFwMgr)Activator.CreateInstance(NetFwMgrType);

// Get the Windows Firewall status
bool firewallEnabled = mgr.LocalPolicy.CurrentProfile.FirewallEnabled;

// it works fine...
String frw_status = "Windows Firewall is "   (firewallEnabled ?
    "enabled" : "disabled");

// Enable or disable firewall.

// I get the exception here when I try to disable Windows Firewall.
// I have not problem when I try to enable Windows Firewall (it works fine).
//
// Exception message:
//   An unhandled exception of type 'System.NotImplementedException' 
//   occurred in net_sandbox.exe
//   Additional information: Method or operation is not emplemented yet..
mgr.LocalPolicy.CurrentProfile.FirewallEnabled = false;

How can I disable Windows Firewall?

Solution

It seems you're using Windows XP SP2 COM API, which is known to have issues on Windows Vista/7 and newer versions.

It's recommended that you use the newer API:

(I have not tested this)

Type netFwPolicy2Type = Type.GetTypeFromProgID("HNetCfg.FwPolicy2");
INetFwPolicy2 mgr = (INetFwPolicy2)Activator.CreateInstance(netFwPolicy2Type);

// Gets the current firewall profile (domain, public, private, etc.)
NET_FW_PROFILE_TYPE2_ fwCurrentProfileTypes = (NET_FW_PROFILE_TYPE2_)mgr.CurrentProfileTypes;

// Get current status
bool firewallEnabled = mgr.get_FirewallEnabled(fwCurrentProfileTypes);
string frw_status = "Windows Firewall is "   (firewallEnabled ?
"enabled" : "disabled");

// Disables Firewall
mgr.set_FirewallEnabled(fwCurrentProfileTypes, false);