> Well assuming he knows what block he wants to remove he can place
> the machine.config file in a DOM, XPath to the node that he wants
> to remove & replace it. If he also wants to delete the preceding
> node if it is a comment he can simply check if its preceding
> sibling is a comment (and examine its text if necessary) then
> remove it as well.
The first assumption is the problem.
<appSettings>
<!-- settings related to X -->
<add key="a" value="1"/>
<add key="b" value="2"/>
<!-- settings related to Y -->
<add key="c" value="3"/>
<add key="d" value="4"/>
</appSettings>
