The XML Viewer is indeed an excellent viewer and I would like to add my thanks.  I'm not doing so well on the editing however - I want to cut and paste a section and then modify it but Paste on the tool bar is disabled.  It's there with a right click but doesn't do anything.  I can add a new child element OK but this is a bit laborious when the data is already almost there.  What do I need to do to enable paste?  Is that what the donate button does? 

No, I'm trying to create siblings to an existing child. 

The section in bold below is what I want to copy.  The bit in italics I did with right-click, Add in the right-hand column.  I did succeed in pasting into category 117 in the XML Source pane.

<PACategory Id="116">

<XMLElementName>StdRptsCategory</XMLElementName>

<Identifier>116</Identifier>

<DisplayNameDescription>#8116</DisplayNameDescription>

<CategoryType>R</CategoryType>
<!-- Shabra, you need to create the other report categories that we need, e.g. DISK, OLDSTATS, USER1 - USERn  -->

<PAReportCategory Id="CPU">


<Identifier>CPU</Identifier>


<DisplayNameDescription>#NNNN</DisplayNameDescription>

</PAReportCategory>

<PAReportCategory iD="DISK"/></PACategory>

Oh and a CtrlZ to undo the last action would be excellent!

No, I think there is still hope!  I'm viewing the XML in XML Viewer and I want to copy the XML that I showed in Bold, insert it straight afterwards and then change where it says CPU to something else, creating a new child.  Does that make sense?  Is it possible?

It not only makes sense but it works perfectly, as required! 
To summarise I need to select on the right hand pane before copying and then select the parent node in the same pane before pasting. 
I wasn't expecting to to be looked after so well!