You need at least ACR 8.2 to work with images from the 70D, so updating your software to ACR 6.7.1, which is the last version compatible with CS5 isn’t going to help.
You need PS-CS6 or PS-CC to be able to update ACR to a version that supports your camera. Your OS is new enough to host either of these.
You can also download the Adobe DNG Converter 8.2 or newer and convert the CR2s to DNGs that would be supported by the older CS5 ACR 6.x, provided you set the DNG compatibility options to something low enough to support the ACR version you have. The default DNG compatibility is ACR 7.1 which would be too new.
You also seem to have a problem with the AAM that won’t let you install updates, so you probably would want to get that fixed. It is not clear what is wrong, but you could try and do what the error message says and reinstall the AAM software.
Here is a relatively recent version of the AAM I found by Googling:
Be aware that the AAM is likely to be superceded by the Creative Cloud Manager app, though the AMM is still there, behind the scenes.
What happens if you do Help / Updates from within PS-CS5? That normally runs the AAM, too. Does that give you the same error?
Thanks for the prompt reply.
The news that I can't utilize Camera Raw with my current version of Photo Shop is a disappointment, but knowing keeps me from wasting more of my time. Purchasing an update to Photo Shop or paying a monthly fee is not an option for me.
Thanks for making me aware of the DNG convertor. I may give it a try one of these days.
I reinstalled AAM several times before I asked for help. Running Help/Updates does not indicate any problem with the AAM. I only have a problem installing Camera Raw. Now that I have found out it won't support my camera it is no longer important.
Thanks again for the information.