System Widget

A tiny always-on-top gauge for Windows showing GPU power draw, VRAM, CPU and RAM at a glance.

Read this in Français.

It sits above the taskbar and never disappears behind it, because the executable is built with the uiAccess privilege — the same one the Magnifier and the on-screen keyboard use. It re-asserts topmost only when the taskbar has actually covered it, instead of twice a second — no flicker.

Temperatures: the GPU thermometer shows the NVIDIA core temperature (via nvidia-smi, no driver involved). The CPU thermometer reads the CPU's own sensor ("CPU Package", or Tctl/Tdie on AMD) through the embedded LibreHardwareMonitor 0.9.6 (MIT) — the engine behind most sensor tools. Reading that sensor means talking to the CPU directly, which no user-mode program may do, so a kernel driver is required; see The CPU sensor driver below. The read also needs administrator rights: the installer starts the widget elevated, and Start with Windows registers a scheduled task with highest privileges, so no UAC prompt appears at logon. Without either the driver or those rights the thermometer stays blank rather than showing a made-up number. The shipped binaries live in lib/ (LibreHardwareMonitor and its runtime dependencies, MIT) — everything else builds from source.

Install

1. Download the repository as a ZIP (or Code → Download ZIP at the top of this page)
2. Extract it anywhere
3. Double-click Installer.bat and accept the administrator prompt

Three clicks, nothing to type, and you can read every line before running it — the sensible habit for a program that installs a driver.

Closed the widget by hand? Double-click Launch.bat to bring it back — no reinstall needed. If it is not installed yet, it offers to run the installer.

Updating later takes one click: the widget watches this repository, turns its border orange when a newer version exists, and Update available in the right-click menu downloads and installs it.

One-line install (usually blocked by Defender)

irm https://raw.githubusercontent.com/Defacedz/system-usage-widget/main/web-install.ps1 | iex

Recent Microsoft Defender builds refuse to run this: download-and-execute in one line is the exact command shape of a malware dropper, so it is killed before it starts (Trojan:Win32/Commando.A!ml; PowerShell just reports Access denied). The detection is about the shape of the command, not about what it downloads — nothing is wrong with your machine. Use the ZIP above instead.

What the installer does

• Builds SystemWidget.cs on your machine with the C# compiler already included in Windows. Nothing is downloaded beyond this repository's source, and no build toolchain is needed.
• Creates a self-signed certificate CN=SystemWidget Local and adds it to the machine's trusted root store. Windows only grants uiAccess to a signed executable installed under Program Files, so both steps are mandatory for the widget to stay above the taskbar. Adding a root certificate is not a trivial change — see Uninstall to remove it.
• Copies the signed binary to C:\Program Files\SystemWidget\ and starts it.

Features

• GPU W — power draw as a percentage of the card's limit
• VRAM — video memory in use
• CPU — total processor usage
• RAM — physical memory in use
• Continuous colour gradient: green when idle, amber, then red near the limit
• Gets out of the way of games: hides itself while a full-screen app is in the foreground, including borderless-fullscreen, and stops re-asserting topmost so it cannot kick a game out of its display mode
• Hover any gauge for exact figures (watts, GB, engine load)
• Drag to move, position is remembered; adjustable opacity; optional start with Windows
• English, Français, Español, Deutsch — right-click → Language
• Two themes — right-click → Theme: the original Dark, or Ivory, built on Anthropic's palette so the panel sits on a light Windows taskbar instead of punching a black hole in it
• Built-in updates — the widget checks this repository every 6 hours, and on every Refresh click; when a newer version is published the border turns Claude-orange and an Update available entry appears at the top of the right-click menu

Requirements

• Windows 10 or 11
• .NET Framework 4.x (present on every supported Windows — nothing to install)
• NVIDIA GPU for the GPU and VRAM gauges: they read nvidia-smi, which ships with the NVIDIA driver. On any other card those two gauges show --; CPU and RAM keep working.

How the readings are taken

Gauge	Source
CPU	GetSystemTimes, sampled once per second
RAM	GlobalMemoryStatusEx
GPU W, VRAM	nvidia-smi --query-gpu=..., one hidden invocation per second

Those four readings use documented Windows APIs and nvidia-smi only. The CPU temperature is the one exception, and it needs a kernel driver:

The CPU sensor driver

CPU temperature lives in a register only kernel code may read. LibreHardwareMonitor 0.9.6 reads it through PawnIO, a signed driver that runs small verified modules instead of handing ring 0 to whoever asks. The installer downloads and installs it for you, from its official release, after checking the exact SHA-256 of the file and its Authenticode signature. If that fails, installation carries on and the CPU thermometer simply stays blank.

PawnIO is a separate program: remove it from Settings → Apps like any other. The widget keeps working without it.

If you installed a build from before September 2026, it embedded LibreHardwareMonitor 0.9.3, which uses WinRing0 — a driver on Microsoft's vulnerable-driver blocklist (CVE-2020-14979: any local program can reach ring 0 through it), which recent Defender builds flag as VulnerableDriver:WinNT/Winring0. Updating removes it: the installer stops and deletes the R0SystemWidget service and its SystemWidget.sys file. That is why this change exists.

Apart from that driver the widget runs as your own user, reads nothing else, accesses no network and sends no telemetry.

Adding a language

Everything lives in the I18n class in SystemWidget.cs. Copy one of the English() / French() blocks, translate the values, and append it to Catalog:

public static readonly Strings[] Catalog = { English(), French(), Spanish(), German(), Italian() };

The language menu and the config file are both driven by Catalog — there is nothing else to wire up. Save the file as UTF-8 with a BOM; pull requests welcome.

Troubleshooting

GPU and VRAM show --. nvidia-smi was not found or returned nothing. The widget looks in System32 and in Program Files\NVIDIA Corporation\NVSMI, then falls back to PATH. On a non-NVIDIA card this is expected. Hover the GPU gauge: the tooltip carries the exact reason, including what nvidia-smi answered.

The GPU gauge shows a percentage but no wattage in its tooltip. That card does not report power.draw — common on laptop GPUs. The gauge falls back to the engine load, and the tooltip says so. Every other field is read independently, so a missing one never blanks the rest.

The widget vanished. A full-screen application is in the foreground; it comes back on its own. Untick Hide in full-screen apps to keep it visible over full-screen video, at the cost of it reappearing over games.

Uninstall

1. Right-click the widget → Quit
2. Delete C:\Program Files\SystemWidget
3. Delete %APPDATA%\SystemWidget
4. Remove the certificate: certlm.msc → Trusted Root Certification Authorities → Certificates → delete SystemWidget Local, then do the same under Trusted Publishers and Personal

License

MIT — see LICENSE.