FIRST EDIT
I'm fetching the Child 1 tag into a DropDownList in my C# form, Plz suggest the best practise code (C#) for deleting a Particular Parent tag & all it's child tags in an XML file. Example of my xml file:

    <Parents>
      <Parent>
        <Child 1>Something</Child 1>
        <Child 2>Something</Child 2>
        <Child 3>Something</Child 3>
        <Child 4>Something</Child 4>
      </Parent>
      <Parent>
        <Child 1>Something 1</Child 1>
        <Child 2>Something 1</Child 2>
        <Child 3>Something 1</Child 3>
        <Child 4>Something 1</Child 4>
      </Parent>
    </Parents>

I mean something like:

for (int i=0; i<[Length of xml doc]; i++)
{
  if (Child 1 == ComboBox1.Text && Child 2 == richTextBox1.Text)
    // Delete <Parent> tag of that Child 1
}