So, I've been seeing lots of different things regarding fighting mouse acceleration in XP: patchers (accelfix), registry tweaks (insert any .reg tweak here), software from manufacturers (mouseware, setpoint) and so on.

The thing is, I always thought I need some external software or whatever to disable acceleration from the windows 2k/xp. I had some extra time after I finally managed to install WinXP with SP3 on this machine. I've had xpsp3 on my laptop for some time now and I noticed some strange things there regarding mouse so here we go...


System setup:

Windows XP professional Service Pack 3 build 5512 (final retail)

Logitech G5 and G9 mice without manufacturer's drivers (Windows default USB hid class driver was used (HID-compliant mouse))

ezQuake 1.9 stable
Quake3 1.32 / CPMA
Unreal2
Unreal Tournament 2004
Armed Assault
Tomb Raider Legend
Tomb Raider Anniversary
STALKER Shadow of Chernobyl

In Windows mouse control panel, toggle between "enhance pointer precision" enabled and disabled.


Results:

ezQuake: I changed modes between in_mouse and in_m_os_parameters and the result was just different sensitivity. When I enabled "enhance pointer precision" I got huge sensitivity boost and very annoying acceleration.

Q3/CPMA: Like in ezQuake, you can choose between in_mouse 1 (direct input) and in_mouse -1 (W32 mouse). There is no mouse acceleration if direct input is used regardless of the mouse control panel setting. When using W32mouse and "enhance pointer precision" sensitivity is really high and there is some mouse acceleration. Disable "enhance pointer precision" and you get sensitivity reduced with absolutely no acceleration.

Unreal2: No acceleration when "enhance pointer precision" is disabled.

ut2k4: No acceleration when "enhance pointer precision" is disabled.

ArmA: No acceleration when "enhance pointer precision" is disabled.

TRLegend: Strange sensitivity change on 3rd person free cam mode depending on something, not the movement speed of mouse. When in manual aim mode (behind the shoulder with manual aiming) there is no acceleration or mouse sensitivity changes. Conclusion: Input seems to behave differently on different situations.

TRAnniversary: No acceleration when "enhance pointer precision" is disabled.

STALKER: No acceleration when "enhance pointer precision" is disabled.


Conclusion:

From the looks of it, you won't need any kind of special "hack" to disable acceleration in XP if you use the default USB drivers that ship with XP, just disable that "enhance pointer precision" from the Windows mouse control panel.

This applies to BOTH my laptop and this desktop machine using XPSP3. I decided to give it a try before applying accelfix due to the fact that W2KSP4 behaved the same way with the default USB drivers.

So what causes the acceleration? Who knows, perhaps it's related to mouse manufacturer's drivers or even the mouse itself. I know I didn't need any acceleration fix with my MX510 either (W2KSP4) but I do remember needing accelfix on earlier life with Logitech mouse driver on both OSes, XP and W2K. Or perhaps it's just people not unticking that option in the mouse cpl that I mentioned like 1000 times already.


Feel free to discuss and post your results. I've given and explained one scenario with few results so try that or something of your own.


EDIT: Some older games that explicitly refuse to use proper input, seem to be affected. To fix this you will need that accelfix.exe (14.7.2006 version) and run it on safe mode.

There are a few games where there is mouse accel even when enhance point precision is unchecked. However, I doubt anybody here plays Halo PC competitively (like I did over 2 years ago) so it probably doesn't matter

And there are games that do not have static sensitivity, ie. it could change depending on the frames per second you're getting (like lost planet: extreme condition and few others).

Well u can never be sure can you. Just use the acccelfix for xp and you are set

Of course I can be sure if I have tested it thoroughly. The problem lies in the games themselves and in the way they process input. Bioshock is a great example of this: no matter what you do to your mouse (accelfix or whatever), the input is still shitty.

Your carefree approach of modifying system level dlls (accelfix modifies win32k.sys) is hilarious. What if you end up booting into a BSOD even in safe mode? Yes, there is that chance always on a system that has different versions of the file depending on the update frequency of the system/automatic updates. A patcher like accelfix could fail on modifying the proper portion of the file.

(I know recovery console and it's usage, however most of the people don't, hence doing something that can potentially damage your OS installation shouldn't be recommended so carefree)

in the past with win98-w2k and xp, unticking enhance pointer precision wasnt enough. Im glad no external fix is required now.

thumbs up renzo

weird that cursor precision = mousefix , shouldn't it be the other way around?

Ive also found that naming "Enhance cursor precision" kinda funny thing. but then again its microsoft.
But its true, you will enable mouse acc by checking it.

Notice that I had already edited the first post regarding certain games about this yesterday. For those few games you actually need an accelfix of some sort (I prefer accelfix.exe) but most of the not so damn old games actually require no accelfixing.