How to shut down Process running in background

New to MACs
I am trying to update from Photoshop CS5 to PS CS6.

The iMAC won't let me and tells me PS is running. It is not up but apparently is running in the background. How do I shut it off so I can update?

Running OS X 10.6.8

Thanks,
Craig

Photoshop should not be running in the background unless something or one of its processes is starting automatically. Anyway do this:

Open your Activity Monitor (Applications, Utilities, Activity Monitor.app) and look for any and all process that are labeled with Photoshop. When you find one highlight the process and press the quit button (looks like a stop sign) at the top menu). That will shut down the process.

After shutting all PS5 processes, you should then be able to install the PS6 upgrade. What I find strange is why the Adobe installer does not already do that for you?

Thank you. I just did that and you are 100% correct in your advice. I agree that it is surprising that the installer does not take care of it.
I'm up and running with CS 6.

Cheers and Thanks!

OK, glad you got it installed. You would think for the price Adobe charges for their software that they would make it easy to install. Have fun with CS6 and visit us often.

Combine my ignorance with service like this and I certainly will! lol

thanks again