How to enable Windows Remote Management (WinRM) for Windows machines
1. On the Windows machine you want to enable WinRM: Click Start, click All Programs, and then click Accessories.
2. Right-click Command Prompt, and then click Run as administrator.
3. If the User Account Control (UAC) dialog box appears, confirm that the action it displays is what you want, and then click Continue.
4. From the command-prompt, type: winrm quickconfig
5. If you see “WinRM is not set up to receive requests on this machine”, it means that it is disabled and must be enabled. Please follow the directions and enable it.
6. If you see WinRM already is set up to receive requests on this machine, you're all set.
How can it be enabled across many machines?
Here's a good Microsoft TechNet article on this.
Essentially, you can use GPO's:
1. Enable listeners
○ To configure the listeners for all computers in a domain, enable the "Allow automatic configuration of listeners" policy in the following Group Policy path:
Computer Configuration\Administrative Templates\Windows Components\Windows Remote Management (WinRM)\WinRM service
○ Enable the policy and specify the IPv4 and IPv6 filters. Wildcards (*) are permitted.
2. Add a firewall exception
Log into your server and press the Start button. Start typing 'firewall' and then click on Windows Firewall with Advanced Security.
Click on Inbound Rules and then find the policy for Windows Remote Management (HTTP-In) and double-click on it.
Click on the Advanced tab and then check the box for Public, click Ok