NWDS error Unable to create part

When trying to edit the view or if I double click the view, an error window comes up with the message: "unable to create part: HelloView".

The Editor tab shows the message "An error has occured when creating this editor".

I got the NWDS from sneak preview.

I searched in forums, I saw one solution by registering the .dll, but that didn't work for me. Please help.

Thanks

Nagesh