How not to throw an exception when trying to write HKLM to standard users?

I am trying to write a value to the HKLM registry using a component TRegistryin Delphi.

Since I work in Windows 2000 as a standard user (or XP as a standard user or Windows Vista as a standard user or Windows 7 with a standard user), I fully expect that I will not be able to write to the HKEY_LOCAL_MACHINEregistry part :

reg := TRegistry.Create(KEY_WRITE);
try
   reg.Access := KEY_WRITE; //sure, set it again, why not
   reg.RootKey := HKEY_LOCAL_MACHINE;
   if not reg.OpenKey('\Software\Microsoft\SQMClient', True) then
      Exit;

   reg.WriteString('MachineId', s);
finally
   reg.Free;
end;

Unfortunately, WriteStringthrows ERegistryException:

Failed to set data for 'MachineId`

This is to be expected, so I am trying to avoid an exception. I do not see any CanWriteStringor TryWriteStringin TRegistry.

How can I not throw an exception when I try to write to HKLM?

Self-explanatory notes:

• ,

• WriteString try-except:

  reg := TRegistry.Create(KEY_WRITE);
  try
    reg.RootKey := HKEY_LOCAL_MACHINE;
    if not reg.OpenKey('\Software\Microsoft\SQMClient', True) then
       Exit;
  
    try
       reg.WriteString('MachineId', s);
    except
       on E:ERegistryException do
          {nothing};
    end;
  finally
    reg.Free;
  end;
  

  .

: RTL:

KEY_WRITE          = (STANDARD_RIGHTS_WRITE or
                        KEY_SET_VALUE or
                        KEY_CREATE_SUB_KEY) and not
                        SYNCHRONIZE;

MSDN:

KEY_WRITE (0x20006)  

STANDARD_RIGHTS_WRITE, KEY_SET_VALUE KEY_CREATE_SUB_KEY.