Today, while helping a client troubleshoot a remote desktop issue, I ran into a problem. Port 3389 was properly open, the Terminal Services service was running normally, and the firewall and everything else were turned off. Yet, the host still couldn’t be accessed remotely, although connections could be established from within the host itself.
After further inquiry, I discovered that the user had applied a security policy to restrict access, but I wasn’t sure what settings had been changed or how to reverse them. I searched online and found a relatively reliable method to share with everyone:
1. Start -> Run -> services.msc to open the Services list.
2. Locate the service starting with “IPSec”, double-click it, and disable it:
