How to quarantine/isolate a laptop?

I have a laptop coming in for forensic examination and I am nervous. The edr software we have on it has a quarantine feature that failed.

So far I have remotely shutdown the computer, reset the users password and disabled the computer account in AD.

I am afraid when I turn it on it will auto connect to the company wifi. I dont have a faraday cage, but would a switch just connected to a power source and nothing else …

computerforensics laptop quarantine