Have you put the downloaded CameraRaw.8bi file in the in the right place?
1. Exit Photoshop Elements 5
2. Open My Computer.
3. Double-click Local Disk (C

.
4. Navigate to Program Files\Adobe\Photoshop Elements 5\Plug-Ins\File Formats.
5. Move the existing Camera Raw.8bi plug-in to another location (for example, a new folder on your desktop). Ensure you keep this version in case you need to revert back.
6. Copy the new Camera Raw plug-in, Camera Raw.8bi, from the download into the same folder as Step 4.
7. Start Photoshop Elements.
Hope that helps.