OffNet is a lightweight Windows 10/11 tray application for enabling and disabling network devices directly at the Windows **PnP/driver level** and for monitoring the traffic.
- Small C# / WinForms application; no Electron or browser runtime.
- Uses Windows SetupAPI / Configuration Manager APIs for network-device control.
- Persistent device disable through
CM_Disable_DevNode(..., CM_DISABLE_PERSIST). - Tray status indicator:
- Green by default: at least one managed device is enabled and Windows reports Internet access.
- Red by default: managed devices are disabled at PnP/driver level.
- Blinking yellow by default: a managed device is enabled, but Windows reports no Internet access.
- Tray actions: Activate, Disable, and Reconnect.
- Reconnect runs DHCP release/renew for IPv4 and IPv6 without showing a console window.
- Per-device Tray control selection so physical adapters can be managed without disabling every WAN miniport or virtual adapter.
- Optional rolling traffic graph directly inside the tray menu.
- Optional permanent, click-through throughput meter visually embedded in the Windows taskbar.
- UI languages: English (default), German, and French.
- Configurable tray-state colors and traffic-graph colors.
- Optional automatic startup at Windows sign-in.
- Project link available from the Options dialog.
- No telemetry and no cloud dependency.
- MIT licensed.
OffNet does not merely disconnect a network profile or disable a logical interface. The Disable action disables the selected Windows PnP device node itself. This is comparable to disabling a device in Device Manager and remains disabled across reboot when the Windows API accepts CM_DISABLE_PERSIST for the device.
Software running with ordinary user privileges cannot simply re-enable such a device through normal network-interface APIs. Software running with administrator or SYSTEM privileges can still re-enable Windows PnP devices; OffNet is not intended to override Windows administrator authority.
A left or right click on the tray circle opens the same deliberately compact context menu:
- Activate
- Disable
- Reconnect
- Open OffNet...
- Options...
- Exit
If the optional traffic overview is enabled, its graph is shown above these actions.
The context menu uses normal Windows popup behavior: clicking anywhere outside it closes the menu immediately.
The project link is intentionally kept inside Options rather than the tray menu. Windows Device Manager remains accessible from the main OffNet window.
The tray menu can display a continuously updated rolling traffic graph.
Default history length: 1 minute
The history length is configurable in Options with a slider from 10 seconds to 10 minutes in 10-second steps.
Three independently colored curves are available:
- Download — receive throughput on OffNet-managed network adapters, in Mbit/s.
- Upload — send throughput on OffNet-managed network adapters, in Mbit/s.
- Offline activity — combined receive + send throughput on other active adapters, but only during periods in which all OffNet-managed adapters are disabled.
Download and upload share the same graph and can overlap. Their separate colors make them distinguishable.
The third curve is intentionally shown only for disabled periods. This makes it possible to notice traffic through another adapter even though the adapters controlled by OffNet are supposed to be offline.
Traffic sampling is derived from the selected history window and measurement-point count. The default is 1 minute / 75 points, which is approximately one measurement every 0.8 seconds.
No external server is contacted for the traffic graph. OffNet reads local Windows network-interface byte counters.
The Options dialog allows you to change:
- Language: English / German / French
- Active + Internet tray-circle color
- Disabled tray-circle color
- Active but no Internet tray-circle color
- Show or hide the traffic overview in the tray menu
- Show or hide the permanent taskbar throughput meter
- Traffic history window (10 seconds to 10 minutes)
- Measurement points (10 to 300)
- Download curve color
- Upload curve color
- Offline-activity curve color
- Start OffNet automatically when you sign in to Windows
- Open the OffNet project page on GitHub
The no-Internet tray state blinks between the chosen color and a lighter version of the same color.
Settings are stored in:
%LOCALAPPDATA%\OffNet\settings.ini
Managed device instance IDs are stored separately in:
%LOCALAPPDATA%\OffNet\managed_devices.txt
Because OffNet needs elevated privileges for PnP/driver-level device control, the automatic-start option does not use the ordinary Startup folder or HKCU\...\Run registry value. Instead, OffNet registers a per-user Windows Task Scheduler task with an At log on trigger and highest privileges. Disabling the checkbox removes that task.
The task points to the current OffNet.exe. OffNet only changes the scheduled task when the automatic-start checkbox itself is changed. If the application is moved to another folder, disable and re-enable the automatic-start option once so the task is registered with the new executable path.
OffNet is intentionally kept simple and runtime-light. On a Windows machine, run:
Build_OffNet.cmd
The script looks for the classic .NET Framework C# compiler (csc.exe) and creates:
OffNet.exe
You can also run:
Start_OffNet.cmd
If the EXE does not exist yet, the script builds it first and then starts it.
The generated EXE includes a manifest that requests administrator privileges because PnP device state changes require elevation.
Reconnect executes the equivalent of:
ipconfig /release *
ipconfig /release6 *
ipconfig /renew *
ipconfig /renew6 *
Statically configured addresses are not converted to DHCP addresses by OffNet.
Disabling the physical network adapter currently carrying an RDP, VPN, TeamViewer, AnyDesk, or other remote session can disconnect that session immediately. OffNet asks for confirmation before disabling managed devices.
OffNet is released under the MIT License. See LICENSE.
- Language, tray colors, traffic history and graph options are applied independently from Windows autostart.
- The Task Scheduler entry is modified only when the Start OffNet automatically when I sign in to Windows checkbox actually changes.
- A Windows autostart error therefore no longer prevents a runtime language change or any other OffNet option from being saved.
- Scheduled-task registration now uses the running executable's resolved path and no unnecessary working-directory field.
OffNet can optionally show a lightweight, click-through throughput meter directly over the Windows taskbar. It shares the same rolling history and colors as the tray-menu graph and displays Download, Upload, and Offline activity in Mbit/s. The graph scale follows the highest visible value in the selected rolling time window and can move both upward and downward as old peaks leave the history.
The meter background is transparent, so the current Windows taskbar appearance remains visible underneath it.
Version 1.3.1 improves the optional permanent Windows-taskbar throughput meter:
- OffNet explicitly reapplies the Win32 topmost Z-order while the meter is visible using
SetWindowPos(..., HWND_TOPMOST, ... SWP_NOACTIVATE ...). - The meter remains click-through and does not take keyboard focus.
- Z-order and position are refreshed periodically while the meter is enabled, preventing the taskbar compositor from visually covering it after focus changes.
- Current Download, Upload and Offline-activity values are arranged horizontally instead of being squeezed into three vertical rows.
- The taskbar meter font is selectable in Options from the fonts installed on Windows.
- Default meter font: Segoe UI Semibold.
- If a configured font is unavailable, OffNet falls back safely to Segoe UI Semibold / Segoe UI.
- The Options dialog is resizable and scrollable so future options remain accessible on smaller displays.
The traffic options include a Measurement points slider from 10 to 300 points. The default is 75.
OffNet distributes the requested measurements across the complete selected rolling history:
sample interval = history duration / measurement points
Examples:
- 1 minute / 75 points ≈ 0.8 seconds per measurement
- 1 minute / 300 points = 0.2 seconds per measurement
- 10 seconds / 300 points ≈ 0.033 seconds per measurement
- 10 minutes / 75 points = 8 seconds per measurement
- 10 minutes / 10 points = 60 seconds per measurement
This keeps memory usage bounded and lets the user choose the desired graph resolution without storing an unnecessarily large history.
The tray-menu statistics graph supports:
- Light
- Dark
- Sepia
- Ocean
- Matrix
- Hellfire
- Purple
- Aurora
The selected theme styles the graph background, grid, borders and supporting text. The separately configured Download, Upload and Offline-activity curve colors are preserved.
The permanent Windows-taskbar meter deliberately stays transparent so the real taskbar color, accent and transparency remain visible underneath it.
Version 1.3.3 removes the additional small OffNet status circle from the permanent taskbar throughput meter.
The normal OffNet notification-area icon remains the single status indicator:
- active + Internet
- device/driver disabled
- active but no Internet
The permanent throughput meter now contains only the traffic values, rolling graph and dynamic Mbit/s scale.
The throughput Y-axis no longer remains tied to an old peak for the entire history window. OffNet recalculates the graph scale from recent traffic at a configurable interval.
Default: 5 seconds
Options range: 1–30 seconds
The same adaptive scaling is used by both the tray-menu graph and the permanent taskbar meter. This makes low current traffic such as 0.90 Mbit/s visibly occupy the graph after an older high-throughput burst has passed the scale-refresh interval.
When the foreground application covers its monitor in true full-screen mode, OffNet temporarily:
- hides the permanent taskbar throughput meter;
- pauses traffic sampling for both graph views;
- closes an open traffic/tray popup if necessary.
The normal device-control state remains intact. When full-screen mode ends, OffNet re-establishes its byte-counter baselines and resumes monitoring without turning the full-screen pause into an artificial traffic spike.
The complete OffNet GUI can use:
- Muffin
- Light
- Dark
- Sepia
- Ocean
- Matrix
- Hellfire
- Purple
- Aurora
Muffin represents OffNet's original neutral/light appearance.
Theme palettes explicitly define foreground, secondary text, inputs, borders, selection colors and status colors to maintain readable contrast. Statistics themes remain independently selectable.
The permanent taskbar meter now:
- displays current rates with two decimal places, for example
1.23 Mbit; - supports a configurable font;
- provides one Text shadow switch directly below the font option;
- applies the shadow consistently to all three traffic value labels and the dynamic scale label, or to none of them.
Text shadow is disabled by default.
The icon embedded in OffNet.exe is now also reused by the normal OffNet main window and the Options dialog. The application therefore has consistent branding in Explorer, the executable, and WinForms title bars.
Project page: https://github.com/zeittresor/OffNet