Powershell loop? newbie in powershell logic.

Hi All.

I have a challenge regarding a script.

I want to chech if a file exists on a remote virtual server(this works).

if the file exists i want to close down the vm(this works) and remove a legagy adapter from the virtual machine.

so what i need is the logic, to determine if the file is on the VM, if not the powershell script should sleep for 5 minutes, and then try again, and again until the file is there(this is part of a deployment scenario).

Hope someone can help me.