Once you have installed the Premiere Elements 10 HD content, presumably from
and the content has been installed, you should be able to delete the download files.
Delete the downloaded folder to the Recycle Bin, open Premiere Elements 10 to a new project,
work with some of the HD menus. If OK, then clear the Recycle Bin when necessary.
If not OK, go to the Recycle Bin to restore the folder that you deleted.
Please let us know the outcome.