Windows Proxy Settings: Per-User vs Per-Machine

A proxy works for the administrator who entered it, then disappears when another user signs in. That does not automatically mean the server rejected the second user. The configuration may belong to the first user's profile.

Windows Internet Settings has user and machine scopes. The legacy-named policy “Make proxy settings per-machine (rather than per-user)” controls that distinction for the settings it governs. It is different from changing a single value under the current user's registry hive.

Identify the setting's owner

Microsoft's HKLMProxyServer documentation explains the dependency on the machine-scope policy. If your deployment uses that mechanism, apply it through the supported management policy rather than copying an opaque binary registry value from an unrelated workstation.

Registry-copy workarounds describe particular environments, sometimes with different 32-bit and 64-bit behavior. They are not a guarantee that one exported blob is suitable for every Windows version and account.

Then identify the application

Machine scope does not mean every network client reads those settings. A service may use WinHTTP or its own application configuration. Microsoft's WinHTTP and WinINet comparison is useful when separating the networking stack from the account that runs the process.

Keep those two questions in the troubleshooting record: which configuration store is relevant, and which account or policy scope supplies it? A successful request from your desktop browser answers neither question for a background service.

Also distinguish route configuration from authentication. Giving two users the same proxy address does not give them the same account rights, nor should it silently distribute one user's saved password to everyone on the machine.