Delete a Registry key using C#

Question

I am trying to delete a Registry key like this:

RegistryKey oRegistryKey = Registry.CurrentUser.OpenSubKey(
    "Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\FileExts", true);

oRegistryKey.DeleteSubKeyTree(".");

But that is giving me an exception:

Cannot delete a subkey tree because the subkey does not exist

If I change DeleteSubKeyTree to DeleteSubKey, I receive a different exception:

Registry key has subkeys and recursive removes are not supported by this method

Pretty logical errors I think, search them up in regedit.exe, verify the tree and adjust your code. — Xyv, Aug 27 '15 at 13:08
I've verified this thing its there in the regedit at the same place. not getting what to do now — , Aug 27 '15 at 13:11
So you want to open Software\\Microsoft\\Windows\\CurrentVersion\\Explorer and DeleteSubKeyTree("FileExts"). Easy peasy. Careful with that chainsaw. — Hans Passant, Aug 27 '15 at 13:15
The `o` prefix in your variable `oRegistryKey` represents what is known as [Systems Hungarian](http://stackoverflow.com/a/768316/1497596) notation. Microsoft discourages this variable naming practice when writing code for the .NET Framework. — DavidRR, Jan 10 '17 at 19:21

score 4 · Answer 1 · edited May 23 '17 at 12:13

The approach outlined in this answer is needlessly complex because DeleteSubKeyTree is recursive. From its documentation on MSDN:

Deletes a subkey and any child subkeys recursively.

So, if your goal is to delete the user's FileExts key, do this:

string explorerKeyPath = @"Software\Microsoft\Windows\CurrentVersion\Explorer";

using (RegistryKey explorerKey =
    Registry.CurrentUser.OpenSubKey(explorerKeyPath, writable: true))
{
    if (explorerKey != null)
    {
        explorerKey.DeleteSubKeyTree("FileExts");
    }
}

However, are you sure that you really want to delete a user's FileExts key? I believe that most would consider doing so would be unreasonably destructive and reckless. A more common scenario would be deleting a single file extension key (e.g., .hdr) from the FileExts key.

Finally, note that DeleteSubKeyTree is overloaded. Here is the signature of the second version of this method:

public void DeleteSubKeyTree(
    string subkey,
    bool throwOnMissingSubKey
)

With this version, if subkey does not exist and throwOnMissingSubKey is false, DeleteSubKeyTree will simply return without making any changes to the Registry.

This does not work on Windows 10. The key is definately there... — inexcitus, Jul 30 '21 at 05:45

score 1 · Accepted Answer · edited May 23 '17 at 12:01

1

Try this:

string str = @"Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts";
string[] strSplit = strLocal.Split('\\');
            using (RegistryKey oRegistryKey = Registry.CurrentUser.OpenSubKey(@"Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts", true))
            {
                RegistryKey hdr = oRegistryKey.OpenSubKey(strSplit[strSplit.Length-2], true);
                foreach (String key in hdr.GetSubKeyNames())
                    hdr.DeleteSubKey(key);
                hdr.Close();
                oRegistryKey.DeleteSubKeyTree(strSplit[strSplit.Length - 2]);
            }

Also check: Registry in .NET: DeleteSubKeyTree says the subkey does not exists, but hey, it does!

edited May 23 '17 at 12:01

Community

1
1

answered Aug 27 '15 at 13:13

Rahul Tripathi

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exception : No value exists with that name – Aug 27 '15 at 13:23
thanks for help @Rahul Tripathi the link has worked fine. – Aug 27 '15 at 14:30
This is unnecessary, both DeleteSubKey and DeleteSubKeyTree work with empty string. Key should have write access. – Andrei Kalantarian Sep 29 '21 at 19:35

score 1 · Answer 3 · answered Oct 31 '19 at 10:57

Please pay attention to 32 or 64 registry. NOTE: RegistryView.Registry64 it's the key of the problem.

This is my implementation that works for me:

public static void DeleteRegistryFolder(RegistryHive registryHive, string fullPathKeyToDelete)
{
    using (var baseKey = RegistryKey.OpenBaseKey(registryHive, RegistryView.Registry64))
    {
        baseKey.DeleteSubKeyTree(fullPathKeyToDelete);
    }
}

Usage:

var baseKeyString = $@"SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\MyApp";

DeleteRegistryFolder(RegistryHive.LocalMachine, baseKeyString);

score 0 · Answer 4 · answered Aug 27 '15 at 14:00

0

This will help you ............

http://www.codeproject.com/Questions/166232/C-delete-a-registry-key-cannot-get-it-done

answered Aug 27 '15 at 14:00

score 0 · Answer 5 · answered Sep 29 '21 at 19:40

0

Both methods DeleteSubKey and DeleteSubKeyTree are deleting the current key if the 'subkey' parameter is empty string, like key.DeleteSubKey("");

Key should have write access. It has to be closed/disposed regular way.

answered Sep 29 '21 at 19:40

Andrei Kalantarian

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1
8

score -1 · Answer 6 · answered Aug 27 '15 at 13:15

-1

First you need to check the registry key:

using (RegistryKey Key = Registry.CurrentUser.OpenSubKey(@"Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\FileExts"))
    if (Key != null)
    {    
       key.DeleteValue("."); //delete if exist
    }
    else
    {
        MessageBox.Show("key not found");
    }

answered Aug 27 '15 at 13:15

jiten

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Additional information: No value exists with that name – Aug 27 '15 at 13:24

Delete a Registry key using C#

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