If you have a problem when you right-click on a blank area on the Desktop, then you need to inspect the handlers in this registry key. I don't think ShellExView enumerates the items from here:
HKEY_CLASSES_ROOT \ Directory \ Background \ shellex \ ContextMenuHandlers
The only handler present by default (in a clean XP installation) is the New handler. If you find any additional sub-keys there, it may have be added by third-party applications. Usually, the software that comes with your graphic card adds entries to the above location. Here is one instance, an article from the Intel Graphics Controller website.
It may not be caused by a context-menu handler always, but a PropertySheet handler or an Icon Handler can also be causing the right-click issues. Few have reported that the Property Sheet handler "Property Sheet - IIS W3ext Module" (XP Professional) was responsible for the folder properties issue (See Case:8 in the Symptoms section above), and that reinstalling IIS from Add/Remove Windows Components fixed the problem.
In one peculiar case, it was the shimgvw.dll module Shell Image Verbs - {e84fda7c-1d6a-45f6-b725-cb260c236066} itself causing the problem. In case of system files, try running SFC /Scannow to fix the problem.