Michael,
There are no API calls that search the regisitry for a value. If you know the Key name you can attempt to open it, which will fail if the key doesn't exist. Short of that you'd have to use the RegEnum* functions to iterate the whole registry.
If you are looking to see if the Acrobat Reader is installed use the FindExecuteable() API to check for pdf extension.
>I was wondering if it is best to check the windows registry to find if an application is installed on a work station? And if so, what command or control would I use to find a file name 'AcroRd32.exe' in the registry using code only. I've looked at serveral controls in the files section, but could not find one to do what I want it to do. I would appreciate any help.