How do i automate the process of downloading latest ESXi image from the data source. is there any documentation provided. Please help me in this.
Are you looking to download an image from the VMware website or download an ISO from a datastore etc?
Isn't this a job for Update Manager?
I agree with scott28tt... Sounds like a job for VMware Update Manager. And with PowerCLI you can automate some tasks in VUM.
I believe you can do this using PowerCLI, the following guide explains the process
Create a script to download the files you want, if you want it to occur regularly then you can use a scheduled task
Please don't create new threads asking the same question - I've locked the other one that you posted.
Are you trying to keep copies of lots of different versions of ESXi? If so, why do that, and why not use Update Manager as a number of people have suggested?