The Photoshop Express Uploader is an application based on Adobe AIR. Presumably you downloaded the app after setting up an account at Photoshop.com
If you don’t need it, simply uninstall it.
Windows - Choose Start à Settings à Control Panel à Add Or Remove Programs.
Select Adobe Photoshop.com Uploader and click Remove.
Mac OS - Use the uninstaller, but if you have no alias simply drag the Adobe Photoshop.com Uploader application folder to the trash.