Start by checking that you haven't enabled the Cinema 4D or Raytrace 3D renderer in your comp settings.
The easiest way for us to diagnose a problem is for you to select the layers that are giving you problems, press the U key twice to reveal all modified properties and then use use Shift + Ctrl/Cmnd + 3 to create a screenshot of your comp. It is also a good idea to have the Comp selected in the Project panel so we can see the composition settings. You can then just drag the screenshot to the reply field on the forum. Cropped screenshots are pretty much useless in diagnosing problems.
There are a ton of things that can slow down renders so without more details it's pretty hard to say wha't going on.
I checked and Ray Tracing was the selected renderer. I changed it to classic 3D, re-rendered a test which took 51 seconds instead of 90 minutes.
Thanks for the help. It is much appreciated. Paul
Thanks for the guidance Rick. I think I misunderstood which screen shot helps. I will screenshot the comp next time. Paul