In many cases, resetting the preferences fixes this issue.
Hold down Ctrl+Alt+Shift when launching Photoshop Elements, if you get the timing right, you will be prompted to delete the setting file. Do so.
If you cannot get the dialog to appear, you can delete the file manually: C:\Documents and Settings\[User Name]\Application Data\Photoshop Elements\[Version Number]\
Move the [Version Number] folder to the desktop and retry launching Photoshop Elements.