Deleting a registry key

Deleting a registry key - c#

I am trying to delete a registry key sub tree which happens to be SAPI 5 user profile as shown below. The "nameofprofile" is the data value of the subkey and the subkey name is a CLSID but it comes up with an exception telling me that the subkey does not exist?
RegistryKey RegKey = Registry.CurrentUser.OpenSubKey("Software\\Microsoft\\Speech\\RecoProfiles\\Tokens\\", true);
RegKey.DeleteSubKeyTree("NameOfProfile");

You can try this.
string keyName = #"Software\Microsoft\Speech\RecoProfiles\Tokens";
using (RegistryKey key = Registry.CurrentUser.OpenSubKey(keyName, true))
{
key.DeleteSubKeyTree("NameOfProfile",false);
}
If you get the error again, you can try to run application in administrator mode.

Do a search of the string[] GetSubKeyNames() first and see if the sub key exists.
Try ignoring casing in case that is an issue.
var name = #"Software\Microsoft\Speech\RecoProfiles\Tokens";
var regKey = Registry.CurrentUser.OpenSubKey(name, true);
if (regKey != null) {
using (regKey) {
var subKeyName = "CLSID";
var actual = regKey.GetSubKeyNames()
.FirstOrDefault(n => string.Equals(n, subKeyName, StringComparison.InvariantCultureIgnoreCase));
if (actual != null) {
regKey.DeleteSubKeyTree(actual);
}
}
}

In the end I worked it out myself and I did this which worked fine. I should have said in the post that I always knew the profile name but I did not know the CLSID. No doubt there is an easier way to do this(No special permissions were required which was preferable if possible):
public static void DeleteKey (String profileName)
{
// Folder for SAPI 5 user profile tokens
String keyLocation = #"Software\Microsoft\Speech\RecoProfiles\Tokens";
RegistryKey key = Registry.CurrentUser.OpenSubKey(keyLocation, true);
// Get a list of Key names and work out which one is the "test" profile
String [] subKeyNames = key.GetSubKeyNames();
// Enumerate through the sub key names to find out which one is the "Test" profile
for(int i = 0; i < subKeyNames.Length; i++)
{
RegistryKey subKey =
Registry.CurrentUser.OpenSubKey("Software\\Microsoft\\Speech\\RecoProfiles\\Tokens\\" + subKeyNames[i]);
if(((String)subKey.GetValue("")).Equals(profileName))
{
key.DeleteSubKeyTree(subKeyNames[i]);
return;
}
}
}

Related

How to set a RegistryKey Value in Visual Studio?

I have a Project and i am trying to run the installer on a new pc to test my WPF application, but the registry key is not automatically created. I have tried adding it manually but i don't know why it is not working, i am sure i am not adding the key the right way. Also i am confused since it is a new PC how do i add something that will automatically create a path?
The one that i am creating is something like this in the Image:
[VS Image][1]

HKLM -- do you have Admin right? really privileged rights?
How to test that you have enough right to write to HKLM (just call OpenSubKey):
public bool CanSetRegKeyValue(string path, string valueName, RegistryKey registry = null)
{
bool result = true;
try
{
RegistryKey registryKey = null;
if (registry == null)
{
registryKey = Registry.LocalMachine;
}
using (RegistryKey key = registryKey.OpenSubKey(path, true))
{
result = key != null;
}
}
catch (NullReferenceException)
{
result = false;
}
catch (SecurityException)
{
result = false;
}
return result;
}
and usage sample, which checking write ability to Key DefaultLevel under node HKLM\SOFTWARE\Policies\Microsoft\Windows\safer\codeidentifiers:
bool result = CanSetRegKeyValue("SOFTWARE\\Policies\\Microsoft\\Windows\\safer\\codeidentifiers\\", "DefaultLevel");

C#: Find a key without knowing where it is

I'd like to preface this by highlighting that I am fairly new to C#.
I'm trying to make a program to find and edit a registry value in order to disable CPU core parking using this method: Registry Edit
The issue is that I know the start of the key:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Power\PowerSettings\
But not the Next part but I know the segment after that:
0cc5b647-c1df-4637-891a-dec35c318583
So if it looks like this:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Power\PowerSettings\<UNKNOWN>\0cc5b647-c1df-4637-891a-dec35c318583
How do I find the using Registry and Registrykey? I tried looping through all subkeys and I just get an exception because all I get back is null.
Any suggestions appreciated.

You can use recursion for finding SubKey.
private RegistryKey SearchSubKey(RegistryKey Key,String KeyName)
{
foreach (String subKey in Key.GetSubKeyNames())
{
RegistryKey key1 = Key.OpenSubKey( subKey);
if (subKey.ToUpper() == KeyName.ToUpper())
return key1;
else
{
RegistryKey mReturn = SearchSubKey(key1, KeyName);
if (mReturn != null)
return mReturn;
}
}
return null;
}
Call this function as
RegistryKey key = Registry.LocalMachine.OpenSubKey(#"SYSTEM\ControlSet001\Control\Power\PowerSettings\");
RegistryKey SubKey = SearchSubKey(key, "0cc5b647-c1df-4637-891a-dec35c318583");
This function search through all sub keys in main key recursively. If you want to search up to particular level then you have to add that logic in function.

I guess you forgot to mention the Registry key name in a proper fashion. Here is the piece of code which brings out the output :
class Program
{
static void Main(string[] args)
{
RegistryKey key = Registry.LocalMachine.OpenSubKey("Software\\Microsoft\\Windows\\CurrentVersion");
foreach (var v in key.GetSubKeyNames())
{
RegistryKey key1 = Registry.LocalMachine.OpenSubKey("Software\\Microsoft\\Windows\\CurrentVersion\\" + v);
foreach ( var v1 in key1.GetSubKeyNames())
{
if (v1 == "{00EC8ABC-3C5A-40F8-A8CB-E7DCD5ABFA05}")
Console.WriteLine(key1);
}
}
}
}
Please let me know if this works.

get installed version of an application using c#

I would to get installed version of an application (say, MyApp) using C#.
I will do this much,
1. Create a 'Set Up' for MyApp of version 5.6
2. Install MyApp.
I will create another application (say VersionTracker)to get the version of installed applications. So if I pass the name 'MyApp' I would like to get the version as '5.6'. If another application say Adobe Reader is installed in my system, I want to get the version of Adobe Reader if I pass 'Adobe Reader'.
I need to know how to build 'VersionTracker'

The first and the most important thing is that not all applications do save their version somewhere in the system. To be honest, only a few of them do that. The place where you should look are the Windows Registry. Most of installed applications put their installation data into the following place:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall
However, it's not that easy - on 64bit Windows, the 32bit (x86) applications save their installation data into another key, which is:
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall
In these keys there are many keys, some of them have got "easy-readable" name, such as Google Chrome, some of them got names such as {63E5CDBF-8214-4F03-84F8-CD3CE48639AD}. You must parse all these keys into your application and start looking for the application names. There are usually in DisplayName value, but it's not always true. The version of the application is usually in DisplayVersion value, but some installers do use another values, such as Inno Setup: Setup Version, ... Some application do have their version written in their name, so it's possible that the application version is already in the DisplayName value.
Note: It's not easy to parse all these registry keys and values and to "pick" the correct values. Not all installers save the application data into these keys, some of them do not save the application version there, etcetera. However, it's usual that the application use these registry keys. [Source: StackOverflow: Detecting installed programs via registry, browsing my own registry]
Alright, so now when you know where you should look, you have to program it all in C#. I won't write the application for you, but I'll tell you what classes you should use and how to. First, you need these:
using System;
using Microsoft.Win32;
To get to your HKEY_LOCAL_MACHINE, create a RegistryKey like this:
RegistryKey baseRegistryKey = Registry.LocalMachine;
Now you need to define subkeys:
string subKey = "SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Uninstall";
// or "SOFTWARE\\Wow6432Node\\Microsoft\\Windows\\CurrentVersion\\Uninstall"
Now you need to go to the subkey, so create a new RegistryKey:
RegistryKey uninstallKey = baseRegistryKey.OpenSubKey(subKey);
Now you need to go thru all the subkeys that are there, so first we get the names of all the subkeys:
string[] allApplications = uninstallKey.GetSubKeyNames();
Now you must go thru all the subkeys yourself, one by one, by creating a new registry key (you don't have to, but I'll do it):
RegistryKey appKey = baseRegistryKey.OpenSubKey(subKey + "\\" + applicationSubKeyName);
where applicationSubKeyName is the name of the subkey you're currently checking. I recommend foreach statement, which helps you (you must however have some experience with C# already, I'm not going to tell you how to use foreach here).
Now check the application's name and compare it with name of your desired application (you cannot rely on the subkey name, because, as I already said, they can be called for example {63E5CDBF-8214-4F03-84F8-CD3CE48639AD}, so you must check the name here):
string appName = (string)appKey.GetValue("DisplayName");
If it's the correct application (you must check it yourself), find the version:
string appVersion = (string)appKey.GetValue("DisplayVersion");
Et voilà, you have the version. At least there's like a 60 - 80% chance you have...
Remember! If some key or value doesn't exist, the method returns null. Remember to check if the returned value is null everytime, otherwise your application will crash.
Where to find more? The Code Project: Read, write and delete from registry with C#
I really hope I helped you. And if you wanted to know something else and I didn't understand your question, then, please, ask better next time. :)

///
/// Author : Muhammed Rauf K
/// Date : 03/07/2011
/// A Simple console application to create and display registry sub keys
///
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
// it's required for reading/writing into the registry:
using Microsoft.Win32;
namespace InstallationInfoConsole
{
class Program
{
static void Main(string[] args)
{
Console.WriteLine("Registry Information ver 1.0");
Console.WriteLine("----------------------------");
Console.Write("Input application name to get the version info. (for example 'Nokia PC Suite'): ");
string nameToSearch = Console.ReadLine();
GetVersion(nameToSearch);
Console.WriteLine("----------------------------");
Console.ReadKey();
}
///
/// Author : Muhammed Rauf K
/// Date : 03/07/2011
/// Create registry items
///
static void Create()
{
try
{
Console.WriteLine("Creating registry...");
// Create a subkey named Test9999 under HKEY_CURRENT_USER.
string subKey;
Console.Write("Input registry sub key :");
subKey = Console.ReadLine();
RegistryKey testKey = Registry.CurrentUser.CreateSubKey(subKey);
Console.WriteLine("Created sub key {0}", subKey);
Console.WriteLine();
// Create two subkeys under HKEY_CURRENT_USER\Test9999. The
// keys are disposed when execution exits the using statement.
Console.Write("Input registry sub key 1:");
subKey = Console.ReadLine();
using (RegistryKey testKey1 = testKey.CreateSubKey(subKey))
{
testKey1.SetValue("name", "Justin");
}
}
catch (Exception e)
{
Console.WriteLine(e.Message);
}
}
static void GetVersion(string nameToSearch)
{
// Get HKEY_LOCAL_MACHINE
RegistryKey baseRegistryKey = Registry.LocalMachine;
// If 32-bit OS
string subKey
//= "SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Uninstall";
// If 64-bit OS
= "SOFTWARE\\Wow6432Node\\Microsoft\\Windows\\CurrentVersion\\Uninstall";
RegistryKey unistallKey = baseRegistryKey.OpenSubKey(subKey);
string[] allApplications = unistallKey.GetSubKeyNames();
foreach (string s in allApplications)
{
RegistryKey appKey = baseRegistryKey.OpenSubKey(subKey + "\\" + s);
string appName = (string)appKey.GetValue("DisplayName");
if(appName==nameToSearch)
{
string appVersion = (string)appKey.GetValue("DisplayVersion");
Console.WriteLine("Name:{0}, Version{1}", appName, appVersion);
break;
}
}
}
static void ListAll()
{
// Get HKEY_LOCAL_MACHINE
RegistryKey baseRegistryKey = Registry.LocalMachine;
// If 32-bit OS
string subKey
//= "SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Uninstall";
// If 64-bit OS
= "SOFTWARE\\Wow6432Node\\Microsoft\\Windows\\CurrentVersion\\Uninstall";
RegistryKey unistallKey = baseRegistryKey.OpenSubKey(subKey);
string[] allApplications = unistallKey.GetSubKeyNames();
foreach (string s in allApplications)
{
RegistryKey appKey = baseRegistryKey.OpenSubKey(subKey + "\\" + s);
string appName = (string)appKey.GetValue("DisplayName");
string appVersion = (string)appKey.GetValue("DisplayVersion");
Console.WriteLine("Name:{0}, Version{1}", appName, appVersion);
}
}
}
}

Next code base on similar solution is working for me:
var version = GetApplicationVersion("Windows Application Driver");
string GetApplicationVersion(string appName)
{
string displayName;
// search in: CurrentUser
var key = Registry.CurrentUser.OpenSubKey(#"SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall");
foreach (var keyName in key.GetSubKeyNames())
{
var subKey = key.OpenSubKey(keyName);
displayName = subKey.GetValue("DisplayName") as string;
if (appName.Equals(displayName, StringComparison.OrdinalIgnoreCase))
return subKey.GetValue("DisplayVersion").ToString();
}
// search in: LocalMachine_32
key = Registry.LocalMachine.OpenSubKey(#"SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall");
foreach (var keyName in key.GetSubKeyNames())
{
var subKey = key.OpenSubKey(keyName);
displayName = subKey.GetValue("DisplayName") as string;
if (appName.Equals(displayName, StringComparison.OrdinalIgnoreCase))
return subKey.GetValue("DisplayVersion").ToString();
}
// search in: LocalMachine_64
key = Registry.LocalMachine.OpenSubKey(#"SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall");
foreach (var keyName in key.GetSubKeyNames())
{
var subKey = key.OpenSubKey(keyName);
displayName = subKey.GetValue("DisplayName") as string;
if (appName.Equals(displayName, StringComparison.OrdinalIgnoreCase))
return subKey.GetValue("DisplayVersion").ToString();
}
// NOT FOUND
return null;
}

how to insert any value to registry using C#?

I have to insert this to the registry:
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows CE Services\AutoStartOnConnect]
"AutoRun"="d:\\MyFolder\\MyProgram.exe"
How would I do this in C#?

Something like this:
string name = #"SOFTWARE\Microsoft\Windows CE Services\AutoStartOnConnect";
using (RegistryKey key = Registry.LocalMachine.OpenSubKey(name, true))
{
if (key == null)
{
// Whatever you want to do if the key isn't found
}
else
{
key.SetValue("AutoRun", #"d:\MyFolder\MyProgram.exe");
}
}
If you use CreateSubKey instead of OpenSubKey, that will create it if it doesn't already exist (or open it for write otherwise) - but I suspect that in most cases, if the key doesn't exist then that indicates the rest of the system isn't in an appropriate state for your app.

You could use the Registry class:
var path = #"Software\Microsoft\Windows CE Services\AutoStartOnConnect";
using (var key = Registry.LocalMachine.OpenSubKey(path, true))
{
if (key != null)
{
key.SetValue("AutoRun", #"d:\MyFolder\MyProgram.exe");
}
}

Writing to Registry (HKEY_LOCAL_MACHINE) in XP

I am trying to modify a registry key that I have been told controls whether write-caching is enabled on particular hard drives. The key should be: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Enum\IDE\<DiskName>\<SerialNo>\Device Parameters\Disk\UserWriteCacheSetting
However I keep having problems when trying to create this key (as it doesn't exist by default). If I try to open up the ...\Device Parameters\Disk\ with write access I get a SecurityException error; "Requested registry access is not allowed". Now I have added the <requestedExecutionLevel level="requireAdministrator" uiAccess="false" /> flag to my manifest file so as to ensure I have admin access, but I'm still not having any luck.
Any ideas would be great!
static void Main(string[] args)
{
RegistryKey myKey = Registry.LocalMachine.OpenSubKey("SYSTEM\\CurrentControlSet\\Enum\\IDE\\");
foreach (string driveManafacturer in myKey.GetSubKeyNames())
{
RegistryKey driveKey = myKey.OpenSubKey(driveManafacturer);
foreach (string driveID in driveKey.GetSubKeyNames())
{
RegistryKey driveIDKey = driveKey.OpenSubKey(driveID, true);
string driveType = (string)driveIDKey.GetValue("Class");
if (driveType == "DiskDrive")
{
RegistryKey tempKey = driveIDKey.OpenSubKey("Device Parameters\\Disk\\", true);
if (tempKey == null)
{
tempKey = driveIDKey.CreateSubKey("Device Parameters\\Disk\\");
tempKey.SetValue("UserWriteCacheSetting", 0x0);
}
}
}
}
return;
}

I don't have a better suggestion. Try to create registry entry by hand, just to make sure that you can. Then make sure that the application is running with your credentials. Just to eliminate the permission issue.

EDIT: Removed the idea about partial trust ... it turned out that it had nothing to do with the problem.
I tried your code and got the same error - with some modifications it works:
RegistryKey myKey = Registry.LocalMachine.OpenSubKey( "SYSTEM\\CurrentControlSet\\Enum\\IDE\\" );
foreach( string driveManafacturer in myKey.GetSubKeyNames() )
{
RegistryKey driveKey = myKey.OpenSubKey( driveManafacturer );
foreach( string driveID in driveKey.GetSubKeyNames() )
{
RegistryKey subKey = driveKey.OpenSubKey( driveID );
string driveType = (string)subKey.GetValue( "Class" );
if( driveType == "DiskDrive" )
{
RegistryKey tempKey = subKey.OpenSubKey( "Device Parameters", true );
RegistryKey tempKey2 = tempKey.OpenSubKey( "Disk" );
if( tempKey2 == null )
{
tempKey2 = tempKey.CreateSubKey( "Disk" );
tempKey2.SetValue( "UserWriteCacheSetting", 0x0 );
}
}
}
}

Develop Reference

C# (C-Sharp) is a programming language developed by Microsoft that runs on the .NET Framework.