Hi Ravi,
I did solve my problem. The error message "none of the processes are ready to run" occurs when an input to the geoprocess is not available.
In my case the input in question were various databases. Local databases worked but databases on a network drive didn�??t work because the geoprocess didn�??t have permissions to access the network drive.
I could access the network drive while running the tool in ArcMap because I was logged on as administrator. But the geoprocess runs as ArcGISSOC and I had to create a ArcGISSOC windows account on the file server machine and give this account permissions to the folder.
Both the inputs not ready and the permissions are documented in the Esri pages but only a sentence or two for each in all of their documentation so it is not something you might notice.
In another case, a database was locked by another process. Even with permissions this didn�??t work until the lock was released. In my case, the database was locked due to a different ArcGIS problem which I haven�??t solved yet.
Thanks for the help.
Charles