You can upgrade to Camera Raw 6.7, but that's it. There are no more updates available for Photoshop CS5. You are either going to have to upgrade your software or use the latest DNG converter to create digital negative copies of your raw files. Or, you could add Lightroom to your workflow.
Thanks, Jim. No wonder I couldn't make it work. I do have Lightroom 4. So if I bring my photos into Lightroom first will I be able to use my existing Camera Raw when I bring the photos into Photoshop?
First of all, that will depend on the camera. What model are you using? If Lightroom 4 will open the raw files from your camera, then they should be able to go from Lightroom to Photoshop when needed. Have you updated to Lightroom 4.4? That is the last version of Lightroom 4 that was released.
Lightroom 4.4 is compatible with versions of Camera Raw up to version 7.4. So when you try to go from Lightroom to Photoshop you will need to choose the option to render a copy with Lightroom adjustments. Depending on how you have your preferences set, this will create a TIF or PSD file that includes everything you have done in Lightroom and will pass that file to Photoshop where you can finish your work.