Get-Printer and Set-Printer return The spooler service is not reachable. Ensure the spooler service is running.

Cause: RPC network traffic is blocked by Windows Firewall even if Firewall is disabled.

 Solution via GPO:

 1. Open the Group Policy Management Console to Windows Firewall with Advanced Security.
 2. In the navigation pane, click Inbound Rules.
 3. Click Action, and then click New rule.
4. On the Rule Type page of the New Inbound Rule Wizard, click Custom, and then click Next.
5. On the Program page, click This Program Path, and then type %systemroot%\system32\svchost.exe.
 6. Click Customize.
7. In the Customize Service Settings dialog box, click Apply to this service, select Remote Procedure Call (RPC) with a short name of RpcSs, click OK, and then click Next.
8. On the warning about Windows service-hardening rules, click Yes.
9. On the Protocol and Ports dialog box, for Protocol type, select TCP.
10. For Local port, select RPC Endpoint Mapper, and then click Next.
11. On the Scope page, you can specify that the rule applies only to network traffic to or from the IP addresses entered on this page. Configure as appropriate for your design, and then click Next.
12. On the Action page, select Allow the connection, and then click Next.
13. On the Profile page, select the network location types to which this rule applies, and then click Next.

You can perform the same steps on the advanced setting on the windows firewall control panel.
~contributed by David Rowe