This has helped a bit, it makes the game playable but still doesnt feel natural
Secondly (Works with XP, Vista and Windows 7)
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
If done correctly, you will notice you are holding a more responsive mouse (if you have been playing with mouse acceleration turned on for a long time, be warned: it does take some getting used to.)