What is MouseAcceleration doing?

aha aha

ohaaa o:\ it was enabled, omg!

The registry fixes from RaZiel's guide do not really disable the mouseacceleration. They just try to compensate for it by adding something like a "reverse acceleration". Accelfix really disables the acceleration by changing a windows file. This is prolly not really correct, but I'm to tired to look it up (:
If you don't know what mouse accel is, just forget about the patches etc and be happy!

1. Click Start button
2. Select Run
3. Type 'regedit' in the open textbox
4. Open the tree 'HKEY_CURRENT_USER', select control panel, then select mouse
5. Right clicking, modify the SmoothMouseXCurve and SmoothMouseYCurve hexidecimal values to the following:

SmoothMouseXCurve:
00,00,00,00,00,00,00,00
00,a0,00,00,00,00,00,00
00,40,01,00,00,00,00,00
00,80,02,00,00,00,00,00
00,00,05,00,00,00,00,00

SmoothMouseYCurve:
00,00,00,00,00,00,00,00
66,a6,02,00,00,00,00,00
cd,4c,05,00,00,00,00,00
a0,99,0a,00,00,00,00,00
38,33,15,00,00,00,00,00

just remove it with setpoint

It accelerates your mouse!

I got the impression nobody above this line has a clue what he's talking about..

Accelfix patches a pattern in your win32k.sys file, which is the file being also responsible for cursor acceleration. The pattern being patched is the sequence being responsible for (causing) cursor acceleration. In other words there is no way you can get acceleration by windows... though the game / app can still apply custom acceleration. Ofcourse this patch doesn't fix (negative) acceleration caused by hardware or badly written software.

For the registry thingy, the SmoothMouseXCurve/SmoothMouseyCurve settings won't have effect anymore as soon as you did this accelfix patch.

Besides I recommend you to use direct or raw input in games (in case they support it), since they take advantage of the high performance resolution of your mouse.