Tiny tray-only cursor overlay for Windows (single ~30 KB exe, no runtime to install).
- Draws a V arrow or circle at the pointer, above every window - including apps that force their own cursor.
- CPU / GPU temperature in small text at the bottom-right of the primary screen (yellow at 80°, red at 90°).
- Everything is configured from the tray icon's right-click menu. Left-click the icon to toggle the overlay.
Grab MouseOverlay.exe from the Releases page and run it. No installer, no runtime to install (uses the .NET Framework 4.8 that ships with Windows 10/11, x64).
build.cmd
Uses the C# compiler that ships with Windows (%WINDIR%\Microsoft.NET\Framework64\v4.0.30319\csc.exe); no SDK needed.
| Item | Notes |
|---|---|
| Shape / Size / Border width | Arrow tip or circle centre sits exactly on the real hotspot. |
| Center color / Border color / Hollow center | Standard colour picker. |
| Opacity | 25 - 100 %. |
| Real cursor ▸ Replace with overlay shape (default) | The Windows cursor itself becomes the overlay shape. It is drawn by the hardware cursor, so it has zero lag and shows everywhere - including the Start menu, volume / quick-settings flyouts and notification centre, where no app window can draw. The overlay window only appears when an app forces its own cursor, and the real cursor is hidden while it does. |
| Real cursor ▸ Replace arrow only | Same, but text (I-beam), resize, busy and hand cursors keep their normal look. |
| Real cursor ▸ Hide it | Real cursor hidden system-wide (Magnification API), overlay always drawn. Invisible over system flyouts. |
| Real cursor ▸ Leave it | Overlay drawn on top of the untouched real cursor. |
| Hide overlay when app hides cursor | Off by default. Turn on for FPS games that hide the pointer and lock it to the centre, otherwise the overlay sits there like a crosshair. |
| Show CPU / GPU temperature, text size | CPU = hottest ACPI thermal zone (no admin, no driver); GPU = NVIDIA NVML. Non-NVIDIA GPUs show --. |
| Start with Windows | Adds/removes a HKCU\...\Run entry. |
Settings are saved to MouseOverlay.ini next to the exe (or in %LOCALAPPDATA%\MouseOverlay if that folder is not writable).
When Windows shell UI is open (Start, Quick Settings, notification centre, the volume / media OSD, touch keyboard) the app hands the real cursor back for that moment, because no app window can draw over those surfaces.
- Pointer is a per-pixel-alpha layered window; the shape is rendered once, moving it is a single position-only
UpdateLayeredWindowcall. - Position is polled from a dedicated thread on an 8 ms high-resolution timer (no hooks, no raw-input flood, nothing in the input path).
- Z-order is only re-asserted when a foreign visible window actually sits above the overlay (checked 4x/s).
- Temperatures refresh every 2 s and the label only re-renders when the numbers change.
Measured on the dev machine: ~9 MB working set, 0 ms CPU over 20 s while the mouse was moving.
- Exclusive-fullscreen games render straight to the display; no overlay window can draw over them (borderless/windowed works). In Replace mode the real cursor still has the overlay shape there.
- Windows keeps its own UI (Start menu, flyouts, task switcher) in a higher band; the overlay window cannot go above those - that is what Replace mode is for.
- Replaced cursors are restored on exit and on the next launch. If the process is killed, Windows keeps the replaced cursors until you relaunch the app, change the pointer scheme, or sign in again.