What is it?
It is a registry file that removes Windows 7 mouse pointer acceleration.
It is like the CPL Mouse Fix and Cheese Mouse Fix, but gives exactly 1-to-1 mouse to pointer response for Windows 7.
How do you use it?
* Find the display DPI that you currently use:
Click Start, click Control Panel, select Appearance and Personalization, select Display.
See if you have 100% or 125% or 150% selected.
* Open the ZIP file at the link above.
* Select the REG file that matches the DPI% you use and Double-click it.
* Answer Yes, OK to the prompts that appear.
* Reboot or Log off to apply the fix (you have to reboot or Log off).
* Enjoy exactly 1-to-1 mouse to pointer response!
Why do you need the fix?
If you don't know you need it, then you don't need it!
Some older games, such as Quake, Quake 2 and others, while they are active and running, call a Windows function intending to disable variable mouse acceleration by forcing ALL movement to be accelerated by the same amount (doubled).
On Windows 2000 and earlier, that removed all variable acceleration.
Pointing and aiming in those games was OK, because the mouse response was then linear (all movement was accelerated by the same amount; it was doubled).
In XP, Vista and Windows 7, Microsoft changed how mouse pointer acceleration worked.
Now when those games call the function (asking that all movement be accelerated), Windows enables the mouse 'Enhance pointer precision' feature, which adds mouse acceleration using a varying curve to control the mouse response. (It enables it even if you have it turned off in the Control Panel Mouse settings.)
With 'Enhance pointer precision' enabled, slower mouse movements make the pointer go extra slow and faster mouse movements make the pointer go extra fast. It is not linear and not straightline.
This is annoying, because where you are aiming at depends on how far you move your mouse, and also on how fast you moved the mouse to aim. It is not 1-to-1 anymore.
How does the fix work?
It redefines the curve used by the 'Enhance pointer precision' feature to be a completely straight line. The slope of the line is tuned so that every on-mouse-pad mouse movement is turned into exactly the same amount of on-screen pointer movement.
How do you know the fix is working?
You can test if it is working by temporarily turning on the 'Enhance pointer precision' feature and see how the mouse responds.
If you have 'Enhance pointer precision' OFF, then the fix will not be active (it will only be waiting to be activated). Just as some games turn it on when you don't want them to, we can turn it on manually to test that the fix is working properly.
* Go to Control Panel, and select Hardware and Sound, then click Mouse. Select 'Pointer options' and check-ON/enable the 'Enhance pointer precision' option.
* See how the mouse responds.
* If you want, you can run the MouseMovementRecorder.exe program that is included in the ZIP file to see that the mouse and pointer movements are 1-to-1 and always the same.
(The numbers in the DEVICE MOVEMENT column should be the same as the numbers in the CURSOR MOVEMENT column. Any differences will appear in green or red.
If you do sometimes see differences, also test with 'Enhance pointer precision' OFF, in case the problem is with Windows or MouseMovementRecorder.exe rather than a problem with the fix.)
* Turn the 'Enhance pointer precision' option OFF when you have finished testing.
Is this fix different from the Cheese Mouse Fix?
The 'Enhance pointer precision' option works slightly differently in Windows 7 than it does in XP and Vista.
The Cheese Mouse Fix gives exactly 1-to-1 mouse response for Windows XP and Windows Vista.
The MarkC Mouse Fix gives exactly 1-to-1 mouse response for Windows 7.
(Note: Both fixes need the Control Panel 'pointer speed' slider set to the 6th, middle position to give exact 1-to-1.)