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Change Registry Value using C#

Hi,

I have desktop c# application, and when this application main frm loads i want to update some registry value to null ...
the regsitry value resided on:

HKEY_CURRENT_USER\AppEvents\Schemes\Apps\.Default\.Default\.Current

This key have default vallue as (%SystemRoot%\media\Windows XP Ding.wav)

And i just want to replace it with null ! i tried this and didnt work !

RegistryKey rkHKLM = Registry.CurrentUser; ;            
RegistryKey rkRun;
 
rkRun =
rkHKLM.OpenSubKey(@"HKEY_CURRENT_USER\AppEvents\Schemes\Apps\.Default\.Default\.Current", true);
 
rkRun.SetValue("Default", "");                      
Registry.CurrentUser.Flush();

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ASKER CERTIFIED SOLUTION

Jaime Olivares

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Fernando Soto

Hi hammdan_1980;

As per the documentation:
Since many values can be stored in each key in the registry, the name parameter specifies the particular value you want to manipulate. To set the default value for a particular registrykey, name can be set to either a null reference (Nothing in Visual Basic), or the empty string ("").

http://msdn2.microsoft.com/en-us/library/microsoft.win32.registrykey.setvalue(VS.71).aspx

So change this:
rkRun.SetValue("Default", "");
To this:
rkRun.SetValue("", "");
or this:
rkRun.SetValue(null, "");

Fernando

Nasser Hamdan

ASKER

Hi Fernando,
I tried the solution as well read the article,, and tried what is suggesting, but i faced same problem which is exception saying: Object refrence not set to an instance of object.

here is the code again after modify it:

RegistryKey rkHKLM = Registry.CurrentUser;
 
RegistryKey rkRun;
rkRun =
rkHKLM.OpenSubKey(@"HKEY_CURRENT_USER\AppEvents\Schemes\Apps\.Default\.Default\.Current", true);
 
rkRun.SetValue(null, "");              
Registry.CurrentUser.Flush();

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Nasser Hamdan

ASKER

Thanks alot ... i cant believe that it was so easy and i spent 4 hours try to figure it out :(