Courtesy http://www.lemmymorgan.com


XBOX 360 Controller emulator v3.0 for PC games using XINPUT.

This program will add more controller support for Games for Windows.

Notes:
Tested with Logitech Cordless Rumblepad 2 & Logitech G25 Racing Wheel.
Tested with the following PC Games
Juiced 2: HIN
Crysis WARHEAD
GTAIV
GRID
MotoGP 08
The Club
Kane & Lynch
Sega Rally
Bionic Commando
SpiderMan Web of Shadows
Unreal Tournament 3
Shadowrun
Fallout 3
Flatout 2 Ultimate Carnage
and the new
Lord of the Rings Conquest
Mirror's Edge (with some mapping bugs) 

It is not working with
Gears of War
007 Quantum of Solace 

The xinput dll can go by several names, you can rename the dll to those below till you find one that works
xinput9_1_0.dll
xinput1_3.dll
xinput1_2.dll
xinput1_1.dll

GTAIV uses xinput9_1_0.dll