The update from Adobe Lightroom 4.1 to 4.2 worked fine but it left my Adobe Bridge still looking for Adobe Lightroom 4.1. Where do I record the change? I finally made a change in Regedit (which I really shouldn't be playing with). To reflect the change in Bridge you have to close Bridge and reopen it.
I tried to use Bridge to search older CR2 files not yet imported into Lightroom and double-clicked on a thumbnail. Bridge responded with an error message saying it could not locate Adobe Lightroom 4.1 after I had updated to version 4.2. I rarely use Bridge and originally opened it just to check Color Management synchronization between Adobe programs.
I am using CS5.5. When I double-clicked a thumbnail (for a *.cr2 file) in Bridge to open the file it tried to open it with Lightroom 4.1. I too could not find any reference to Lightroom in the preferences or anywhere else in Bridge, and that was the problem since I wanted to change what was apparently the default program for opening CR2 files. I have no idea how Lightroom originally came to be designated as the default program to open the CR2 files.
If you go to the preferences in Bridge, there is an option, "File Type Associations" you can select and you can choose the default program for any file type. It seems to me that if you try to use Lightroom from Bridge it have the potential to really mess up your Lightroom catalog. I would change it to your version of Photoshop for those Canon raw files.
Thanks. When I tried that yesterday it did not change the default program. I tried it today and it works exactly as you say. Perhaps if I had rebooted after what obviously should have worked didn't, I would have seen that it was just another hiccup in my OS, which I should be used to by now.