C# registry problem

[Sean Riker via .NET 247]

I'm writing an executable that will either give or take away access to the TaskManager. The problem is some of the computers on my LAN don't have the subkey. I tried to create it but I got this message:

An unhandled exception of type 'System.UnauthorizedAccessException' occurred in mscorlib.dll
Additional information: Cannot write to the registry key.

Here is my source:


RegistryPermission f = new RegistryPermission(RegistryPermissionAccess.AllAccess, "HKEY_CURRENT_USER\\Software\\Microsoft\\Windows\\CurrentVersion\\Policies");

//Get the names of the subkeys to determine if the subkey "System" already exists.
RegistryKey temp = Registry.CurrentUser.OpenSubKey("Software\\Microsoft\\Windows\\CurrentVersion\\Policies");
foreach(string subKeyName in temp.GetSubKeyNames())
{
if(subKeyName == "System")
{
RegistryKey nrk = temp.OpenSubKey("System" ,true);
nrk.SetValue("DisableTaskMgr","1");
nrk.Close();
}
else
{
RegistryPermission P = new RegistryPermission(RegistryPermissionAccess.Write, "HKEY_CURRENT_USER\\Software\\Microsoft\\Windows\\CurrentVersion\\Policies");
---------------->>> RegistryKey nrk = temp.CreateSubKey("System");
nrk.SetValue("DisableTaskMgr","1");
nrk.Close();
}

As you can see I should theoretically have access because I set the permissions with:
RegistryPermission f = new RegistryPermission(RegistryPermissionAccess.AllAccess, "HKEY_CURRENT_USER\\Software\\Microsoft\\Windows\\CurrentVersion\\Policies");

Any help would be appreciated.

 

[Mattias Sjögren]

Sean,

RegistryKey temp = Registry.CurrentUser.OpenSubKey("Software\\Microsoft\\Windows\\CurrentVersion\\Policies");

You have to open this with write access (pass true as the second
parameter) to create subkeys.

As you can see I should theoretically have access because I set the permissions with:
RegistryPermission f = new RegistryPermission(RegistryPermissionAccess.AllAccess, "HKEY_CURRENT_USER\\Software\\Microsoft\\Windows\\CurrentVersion\\Policies");

No, this line of code doesn't set any permissions. In fact, it doesn't
do much at all since you never use the f object.



Mattias