Question: I would like to know whether there is any way I can run an absolutely unknown executable file without being hacked even if the file contains a lot of malicious code. Is there any program in which I can run it without putting myself in any risk?

Answer: 
If you really want the closest thing to a 100% safe way of running malware:

Create an account with Amazon Web Services, fire up a server but don't connect it to anything (read: put it in its **own** VPC) and do your analysis there. Burn after analyzing. 

Side note: there are some pre-created AMIs in the " Ec2 Market Place" that have malware analysis tools loaded on them already if you feel like getting frisky.
Barring NSA-level attacks that alter hard drive firmware and the like, there is a relatively simple and cheap solution. 

* Buy an extra hard drive that include some sort of free "clone" or "migration" software, or a linux "repair" bootable thumb drive.
* Clone your system's hard drive to the new drive then unplug the new drive.
* Unplug the internet source (router, modem, etc) to stop exfiltration
* Install/run your un-trusted EXE as much as needed.
* Reboot and wipe the main hard drive from a bootable thumb drive.
* Clone the copy back to the main box and reboot.

This lets you run code in your normal setup, locally (w/o net), and be rest assured that no harm will come to your machine or data. You could still get hit with a targeted attack that uses something like fan-based exfiltration, but if you're just worried about ransomware, spyware, or a virus, the copy and restore method is very effective.

Use this routine on an extra $100 computer (refurb on newegg or ebay) if the EXE needs internet.