1. Enable File Sharing
In order to run the prerequisites, you need to run the command to enable file sharing and once done you can create a folder on the Exchange 2019 Server and copy the install files and ISO: netsh advfirewall firewall set rule group="File and Printer Sharing" new enable=Yes
2. Enter PowerShell mode
In order to mount the ISO, you need first type in PowerShell at the command prompt and then press enter.
3. Mount the ISO
You now need to run the command: Mount-DiskImage -ImagePath "C:\Installs\ExchangeServer2019-x64.iso"
4. Navigate to Folder
At the prompt, navigate to the folder where you have copied all the downloads to and run the install files.